1 /* ELF linking support for BFD.
2    Copyright (C) 1995-2024 Free Software Foundation, Inc.
3 
4    This file is part of BFD, the Binary File Descriptor library.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program; if not, write to the Free Software
18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19    MA 02110-1301, USA.  */
20 
21 #include "sysdep.h"
22 #include "bfd.h"
23 #include "bfdlink.h"
24 #include "libbfd.h"
25 #define ARCH_SIZE 0
26 #include "elf-bfd.h"
27 #include "safe-ctype.h"
28 #include "libiberty.h"
29 #include "objalloc.h"
30 #if BFD_SUPPORTS_PLUGINS
31 #include "plugin-api.h"
32 #include "plugin.h"
33 #endif
34 
35 #include <limits.h>
36 #ifndef CHAR_BIT
37 #define CHAR_BIT 8
38 #endif
39 
40 /* This struct is used to pass information to routines called via
41    elf_link_hash_traverse which must return failure.  */
42 
43 struct elf_info_failed
44 {
45   struct bfd_link_info *info;
46   bool failed;
47 };
48 
49 static bool _bfd_elf_fix_symbol_flags
50   (struct elf_link_hash_entry *, struct elf_info_failed *);
51 
52 /* Return false if linker should avoid caching relocation information
53    and symbol tables of input files in memory.  */
54 
55 static bool
_bfd_elf_link_keep_memory(struct bfd_link_info * info)56 _bfd_elf_link_keep_memory (struct bfd_link_info *info)
57 {
58 #ifdef USE_MMAP
59   /* Don't cache symbol nor relocation tables if they are mapped in.
60      NB: Since the --no-keep-memory linker option causes:
61 
62      https://sourceware.org/bugzilla/show_bug.cgi?id=31458
63 
64      this is opt-in by each backend.  */
65   const struct elf_backend_data *bed
66     = get_elf_backend_data (info->output_bfd);
67   if (bed->use_mmap)
68     return false;
69 #endif
70   bfd *abfd;
71   bfd_size_type size;
72 
73   if (!info->keep_memory)
74     return false;
75 
76   if (info->max_cache_size == (bfd_size_type) -1)
77     return true;
78 
79   abfd = info->input_bfds;
80   size = info->cache_size;
81   do
82     {
83       if (size >= info->max_cache_size)
84           {
85             /* Over the limit.  Reduce the memory usage.  */
86             info->keep_memory = false;
87             return false;
88           }
89       if (!abfd)
90           break;
91       size += abfd->alloc_size;
92       abfd = abfd->link.next;
93     }
94   while (1);
95 
96   return true;
97 }
98 
99 asection *
_bfd_elf_section_for_symbol(struct elf_reloc_cookie * cookie,unsigned long r_symndx,bool discard)100 _bfd_elf_section_for_symbol (struct elf_reloc_cookie *cookie,
101                                    unsigned long r_symndx,
102                                    bool discard)
103 {
104   if (r_symndx >= cookie->locsymcount
105       || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
106     {
107       struct elf_link_hash_entry *h;
108 
109       h = cookie->sym_hashes[r_symndx - cookie->extsymoff];
110 
111       while (h->root.type == bfd_link_hash_indirect
112                || h->root.type == bfd_link_hash_warning)
113           h = (struct elf_link_hash_entry *) h->root.u.i.link;
114 
115       if ((h->root.type == bfd_link_hash_defined
116              || h->root.type == bfd_link_hash_defweak)
117              && discarded_section (h->root.u.def.section))
118           return h->root.u.def.section;
119       else
120           return NULL;
121     }
122   else
123     {
124       /* It's not a relocation against a global symbol,
125            but it could be a relocation against a local
126            symbol for a discarded section.  */
127       asection *isec;
128       Elf_Internal_Sym *isym;
129 
130       /* Need to: get the symbol; get the section.  */
131       isym = &cookie->locsyms[r_symndx];
132       isec = bfd_section_from_elf_index (cookie->abfd, isym->st_shndx);
133       if (isec != NULL
134             && discard ? discarded_section (isec) : 1)
135           return isec;
136      }
137   return NULL;
138 }
139 
140 /* Define a symbol in a dynamic linkage section.  */
141 
142 struct elf_link_hash_entry *
_bfd_elf_define_linkage_sym(bfd * abfd,struct bfd_link_info * info,asection * sec,const char * name)143 _bfd_elf_define_linkage_sym (bfd *abfd,
144                                    struct bfd_link_info *info,
145                                    asection *sec,
146                                    const char *name)
147 {
148   struct elf_link_hash_entry *h;
149   struct bfd_link_hash_entry *bh;
150   const struct elf_backend_data *bed;
151 
152   h = elf_link_hash_lookup (elf_hash_table (info), name, false, false, false);
153   if (h != NULL)
154     {
155       /* Zap symbol defined in an as-needed lib that wasn't linked.
156            This is a symptom of a larger problem:  Absolute symbols
157            defined in shared libraries can't be overridden, because we
158            lose the link to the bfd which is via the symbol section.  */
159       h->root.type = bfd_link_hash_new;
160       bh = &h->root;
161     }
162   else
163     bh = NULL;
164 
165   bed = get_elf_backend_data (abfd);
166   if (!_bfd_generic_link_add_one_symbol (info, abfd, name, BSF_GLOBAL,
167                                                    sec, 0, NULL, false, bed->collect,
168                                                    &bh))
169     return NULL;
170   h = (struct elf_link_hash_entry *) bh;
171   BFD_ASSERT (h != NULL);
172   h->def_regular = 1;
173   h->non_elf = 0;
174   h->root.linker_def = 1;
175   h->type = STT_OBJECT;
176   if (ELF_ST_VISIBILITY (h->other) != STV_INTERNAL)
177     h->other = (h->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN;
178 
179   (*bed->elf_backend_hide_symbol) (info, h, true);
180   return h;
181 }
182 
183 bool
_bfd_elf_create_got_section(bfd * abfd,struct bfd_link_info * info)184 _bfd_elf_create_got_section (bfd *abfd, struct bfd_link_info *info)
185 {
186   flagword flags;
187   asection *s;
188   struct elf_link_hash_entry *h;
189   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
190   struct elf_link_hash_table *htab = elf_hash_table (info);
191 
192   /* This function may be called more than once.  */
193   if (htab->sgot != NULL)
194     return true;
195 
196   flags = bed->dynamic_sec_flags;
197 
198   s = bfd_make_section_anyway_with_flags (abfd,
199                                                     (bed->rela_plts_and_copies_p
200                                                      ? ".rela.got" : ".rel.got"),
201                                                     (bed->dynamic_sec_flags
202                                                      | SEC_READONLY));
203   if (s == NULL
204       || !bfd_set_section_alignment (s, bed->s->log_file_align))
205     return false;
206   htab->srelgot = s;
207 
208   s = bfd_make_section_anyway_with_flags (abfd, ".got", flags);
209   if (s == NULL
210       || !bfd_set_section_alignment (s, bed->s->log_file_align))
211     return false;
212   htab->sgot = s;
213 
214   if (bed->want_got_plt)
215     {
216       s = bfd_make_section_anyway_with_flags (abfd, ".got.plt", flags);
217       if (s == NULL
218             || !bfd_set_section_alignment (s, bed->s->log_file_align))
219           return false;
220       htab->sgotplt = s;
221     }
222 
223   /* The first bit of the global offset table is the header.  */
224   s->size += bed->got_header_size;
225 
226   if (bed->want_got_sym)
227     {
228       /* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
229            (or .got.plt) section.  We don't do this in the linker script
230            because we don't want to define the symbol if we are not creating
231            a global offset table.  */
232       h = _bfd_elf_define_linkage_sym (abfd, info, s,
233                                                "_GLOBAL_OFFSET_TABLE_");
234       elf_hash_table (info)->hgot = h;
235       if (h == NULL)
236           return false;
237     }
238 
239   return true;
240 }
241 
242 /* Create a strtab to hold the dynamic symbol names.  */
243 static bool
_bfd_elf_link_create_dynstrtab(bfd * abfd,struct bfd_link_info * info)244 _bfd_elf_link_create_dynstrtab (bfd *abfd, struct bfd_link_info *info)
245 {
246   struct elf_link_hash_table *hash_table;
247 
248   hash_table = elf_hash_table (info);
249   if (hash_table->dynobj == NULL)
250     {
251       /* We may not set dynobj, an input file holding linker created
252            dynamic sections to abfd, which may be a dynamic object with
253            its own dynamic sections.  We need to find a normal input file
254            to hold linker created sections if possible.  */
255       if ((abfd->flags & (DYNAMIC | BFD_PLUGIN)) != 0)
256           {
257             bfd *ibfd;
258             asection *s;
259             for (ibfd = info->input_bfds; ibfd; ibfd = ibfd->link.next)
260               if ((ibfd->flags
261                      & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
262                     && bfd_get_flavour (ibfd) == bfd_target_elf_flavour
263                     && elf_object_id (ibfd) == elf_hash_table_id (hash_table)
264                     && !((s = ibfd->sections) != NULL
265                          && s->sec_info_type == SEC_INFO_TYPE_JUST_SYMS))
266                 {
267                     abfd = ibfd;
268                     break;
269                 }
270           }
271       hash_table->dynobj = abfd;
272     }
273 
274   if (hash_table->dynstr == NULL)
275     {
276       hash_table->dynstr = _bfd_elf_strtab_init ();
277       if (hash_table->dynstr == NULL)
278           return false;
279     }
280   return true;
281 }
282 
283 /* Create some sections which will be filled in with dynamic linking
284    information.  ABFD is an input file which requires dynamic sections
285    to be created.  The dynamic sections take up virtual memory space
286    when the final executable is run, so we need to create them before
287    addresses are assigned to the output sections.  We work out the
288    actual contents and size of these sections later.  */
289 
290 bool
_bfd_elf_link_create_dynamic_sections(bfd * abfd,struct bfd_link_info * info)291 _bfd_elf_link_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info)
292 {
293   flagword flags;
294   asection *s;
295   const struct elf_backend_data *bed;
296   struct elf_link_hash_entry *h;
297 
298   if (! is_elf_hash_table (info->hash))
299     return false;
300 
301   if (elf_hash_table (info)->dynamic_sections_created)
302     return true;
303 
304   if (!_bfd_elf_link_create_dynstrtab (abfd, info))
305     return false;
306 
307   abfd = elf_hash_table (info)->dynobj;
308   bed = get_elf_backend_data (abfd);
309 
310   flags = bed->dynamic_sec_flags;
311 
312   /* A dynamically linked executable has a .interp section, but a
313      shared library does not.  */
314   if (bfd_link_executable (info) && !info->nointerp)
315     {
316       s = bfd_make_section_anyway_with_flags (abfd, ".interp",
317                                                         flags | SEC_READONLY);
318       if (s == NULL)
319           return false;
320     }
321 
322   /* Create sections to hold version informations.  These are removed
323      if they are not needed.  */
324   s = bfd_make_section_anyway_with_flags (abfd, ".gnu.version_d",
325                                                     flags | SEC_READONLY);
326   if (s == NULL
327       || !bfd_set_section_alignment (s, bed->s->log_file_align))
328     return false;
329 
330   s = bfd_make_section_anyway_with_flags (abfd, ".gnu.version",
331                                                     flags | SEC_READONLY);
332   if (s == NULL
333       || !bfd_set_section_alignment (s, 1))
334     return false;
335 
336   s = bfd_make_section_anyway_with_flags (abfd, ".gnu.version_r",
337                                                     flags | SEC_READONLY);
338   if (s == NULL
339       || !bfd_set_section_alignment (s, bed->s->log_file_align))
340     return false;
341 
342   s = bfd_make_section_anyway_with_flags (abfd, ".dynsym",
343                                                     flags | SEC_READONLY);
344   if (s == NULL
345       || !bfd_set_section_alignment (s, bed->s->log_file_align))
346     return false;
347   elf_hash_table (info)->dynsym = s;
348 
349   s = bfd_make_section_anyway_with_flags (abfd, ".dynstr",
350                                                     flags | SEC_READONLY);
351   if (s == NULL)
352     return false;
353 
354   s = bfd_make_section_anyway_with_flags (abfd, ".dynamic", flags);
355   if (s == NULL
356       || !bfd_set_section_alignment (s, bed->s->log_file_align))
357     return false;
358   elf_hash_table (info)->dynamic = s;
359 
360   /* The special symbol _DYNAMIC is always set to the start of the
361      .dynamic section.  We could set _DYNAMIC in a linker script, but we
362      only want to define it if we are, in fact, creating a .dynamic
363      section.  We don't want to define it if there is no .dynamic
364      section, since on some ELF platforms the start up code examines it
365      to decide how to initialize the process.  */
366   h = _bfd_elf_define_linkage_sym (abfd, info, s, "_DYNAMIC");
367   elf_hash_table (info)->hdynamic = h;
368   if (h == NULL)
369     return false;
370 
371   if (info->emit_hash)
372     {
373       s = bfd_make_section_anyway_with_flags (abfd, ".hash",
374                                                         flags | SEC_READONLY);
375       if (s == NULL
376             || !bfd_set_section_alignment (s, bed->s->log_file_align))
377           return false;
378       elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
379     }
380 
381   if (info->emit_gnu_hash && bed->record_xhash_symbol == NULL)
382     {
383       s = bfd_make_section_anyway_with_flags (abfd, ".gnu.hash",
384                                                         flags | SEC_READONLY);
385       if (s == NULL
386             || !bfd_set_section_alignment (s, bed->s->log_file_align))
387           return false;
388       /* For 64-bit ELF, .gnu.hash is a non-uniform entity size section:
389            4 32-bit words followed by variable count of 64-bit words, then
390            variable count of 32-bit words.  */
391       if (bed->s->arch_size == 64)
392           elf_section_data (s)->this_hdr.sh_entsize = 0;
393       else
394           elf_section_data (s)->this_hdr.sh_entsize = 4;
395     }
396 
397   if (info->enable_dt_relr)
398     {
399       s = bfd_make_section_anyway_with_flags (abfd, ".relr.dyn",
400                                                         (bed->dynamic_sec_flags
401                                                          | SEC_READONLY));
402       if (s == NULL
403             || !bfd_set_section_alignment (s, bed->s->log_file_align))
404           return false;
405       elf_hash_table (info)->srelrdyn = s;
406     }
407 
408   /* Let the backend create the rest of the sections.  This lets the
409      backend set the right flags.  The backend will normally create
410      the .got and .plt sections.  */
411   if (bed->elf_backend_create_dynamic_sections == NULL
412       || ! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
413     return false;
414 
415   elf_hash_table (info)->dynamic_sections_created = true;
416 
417   return true;
418 }
419 
420 /* Create dynamic sections when linking against a dynamic object.  */
421 
422 bool
_bfd_elf_create_dynamic_sections(bfd * abfd,struct bfd_link_info * info)423 _bfd_elf_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info)
424 {
425   flagword flags, pltflags;
426   struct elf_link_hash_entry *h;
427   asection *s;
428   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
429   struct elf_link_hash_table *htab = elf_hash_table (info);
430 
431   /* We need to create .plt, .rel[a].plt, .got, .got.plt, .dynbss, and
432      .rel[a].bss sections.  */
433   flags = bed->dynamic_sec_flags;
434 
435   pltflags = flags;
436   if (bed->plt_not_loaded)
437     /* We do not clear SEC_ALLOC here because we still want the OS to
438        allocate space for the section; it's just that there's nothing
439        to read in from the object file.  */
440     pltflags &= ~ (SEC_CODE | SEC_LOAD | SEC_HAS_CONTENTS);
441   else
442     pltflags |= SEC_ALLOC | SEC_CODE | SEC_LOAD;
443   if (bed->plt_readonly)
444     pltflags |= SEC_READONLY;
445 
446   s = bfd_make_section_anyway_with_flags (abfd, ".plt", pltflags);
447   if (s == NULL
448       || !bfd_set_section_alignment (s, bed->plt_alignment))
449     return false;
450   htab->splt = s;
451 
452   /* Define the symbol _PROCEDURE_LINKAGE_TABLE_ at the start of the
453      .plt section.  */
454   if (bed->want_plt_sym)
455     {
456       h = _bfd_elf_define_linkage_sym (abfd, info, s,
457                                                "_PROCEDURE_LINKAGE_TABLE_");
458       elf_hash_table (info)->hplt = h;
459       if (h == NULL)
460           return false;
461     }
462 
463   s = bfd_make_section_anyway_with_flags (abfd,
464                                                     (bed->rela_plts_and_copies_p
465                                                      ? ".rela.plt" : ".rel.plt"),
466                                                     flags | SEC_READONLY);
467   if (s == NULL
468       || !bfd_set_section_alignment (s, bed->s->log_file_align))
469     return false;
470   htab->srelplt = s;
471 
472   if (! _bfd_elf_create_got_section (abfd, info))
473     return false;
474 
475   if (bed->want_dynbss)
476     {
477       /* The .dynbss section is a place to put symbols which are defined
478            by dynamic objects, are referenced by regular objects, and are
479            not functions.  We must allocate space for them in the process
480            image and use a R_*_COPY reloc to tell the dynamic linker to
481            initialize them at run time.  The linker script puts the .dynbss
482            section into the .bss section of the final image.  */
483       s = bfd_make_section_anyway_with_flags (abfd, ".dynbss",
484                                                         SEC_ALLOC | SEC_LINKER_CREATED);
485       if (s == NULL)
486           return false;
487       htab->sdynbss = s;
488 
489       if (bed->want_dynrelro)
490           {
491             /* Similarly, but for symbols that were originally in read-only
492                sections.  This section doesn't really need to have contents,
493                but make it like other .data.rel.ro sections.  */
494             s = bfd_make_section_anyway_with_flags (abfd, ".data.rel.ro",
495                                                               flags);
496             if (s == NULL)
497               return false;
498             htab->sdynrelro = s;
499           }
500 
501       /* The .rel[a].bss section holds copy relocs.  This section is not
502            normally needed.  We need to create it here, though, so that the
503            linker will map it to an output section.  We can't just create it
504            only if we need it, because we will not know whether we need it
505            until we have seen all the input files, and the first time the
506            main linker code calls BFD after examining all the input files
507            (size_dynamic_sections) the input sections have already been
508            mapped to the output sections.  If the section turns out not to
509            be needed, we can discard it later.  We will never need this
510            section when generating a shared object, since they do not use
511            copy relocs.  */
512       if (bfd_link_executable (info))
513           {
514             s = bfd_make_section_anyway_with_flags (abfd,
515                                                               (bed->rela_plts_and_copies_p
516                                                                ? ".rela.bss" : ".rel.bss"),
517                                                               flags | SEC_READONLY);
518             if (s == NULL
519                 || !bfd_set_section_alignment (s, bed->s->log_file_align))
520               return false;
521             htab->srelbss = s;
522 
523             if (bed->want_dynrelro)
524               {
525                 s = (bfd_make_section_anyway_with_flags
526                        (abfd, (bed->rela_plts_and_copies_p
527                                  ? ".rela.data.rel.ro" : ".rel.data.rel.ro"),
528                         flags | SEC_READONLY));
529                 if (s == NULL
530                       || !bfd_set_section_alignment (s, bed->s->log_file_align))
531                     return false;
532                 htab->sreldynrelro = s;
533               }
534           }
535     }
536 
537   return true;
538 }
539 
540 /* Record a new dynamic symbol.  We record the dynamic symbols as we
541    read the input files, since we need to have a list of all of them
542    before we can determine the final sizes of the output sections.
543    Note that we may actually call this function even though we are not
544    going to output any dynamic symbols; in some cases we know that a
545    symbol should be in the dynamic symbol table, but only if there is
546    one.  */
547 
548 bool
bfd_elf_link_record_dynamic_symbol(struct bfd_link_info * info,struct elf_link_hash_entry * h)549 bfd_elf_link_record_dynamic_symbol (struct bfd_link_info *info,
550                                             struct elf_link_hash_entry *h)
551 {
552   if (h->dynindx == -1)
553     {
554       struct elf_strtab_hash *dynstr;
555       char *p;
556       const char *name;
557       size_t indx;
558 
559       if (h->root.type == bfd_link_hash_defined
560             || h->root.type == bfd_link_hash_defweak)
561           {
562             /* An IR symbol should not be made dynamic.  */
563             if (h->root.u.def.section != NULL
564                 && h->root.u.def.section->owner != NULL
565                 && (h->root.u.def.section->owner->flags & BFD_PLUGIN) != 0)
566               return true;
567           }
568 
569       /* XXX: The ABI draft says the linker must turn hidden and
570            internal symbols into STB_LOCAL symbols when producing the
571            DSO. However, if ld.so honors st_other in the dynamic table,
572            this would not be necessary.  */
573       switch (ELF_ST_VISIBILITY (h->other))
574           {
575           case STV_INTERNAL:
576           case STV_HIDDEN:
577             if (h->root.type != bfd_link_hash_undefined
578                 && h->root.type != bfd_link_hash_undefweak)
579               {
580                 h->forced_local = 1;
581                 return true;
582               }
583 
584           default:
585             break;
586           }
587 
588       h->dynindx = elf_hash_table (info)->dynsymcount;
589       ++elf_hash_table (info)->dynsymcount;
590 
591       dynstr = elf_hash_table (info)->dynstr;
592       if (dynstr == NULL)
593           {
594             /* Create a strtab to hold the dynamic symbol names.  */
595             elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init ();
596             if (dynstr == NULL)
597               return false;
598           }
599 
600       char *unversioned_name = NULL;
601 
602       /* We don't put any version information in the dynamic string
603            table.  */
604       name = h->root.root.string;
605       p = strchr (name, ELF_VER_CHR);
606       if (p != NULL)
607           {
608             unversioned_name = bfd_malloc (p - name + 1);
609             memcpy (unversioned_name, name, p - name);
610             unversioned_name[p - name] = 0;
611             name = unversioned_name;
612           }
613 
614       indx = _bfd_elf_strtab_add (dynstr, name, p != NULL);
615 
616       if (p != NULL)
617           free (unversioned_name);
618 
619       if (indx == (size_t) -1)
620           return false;
621       h->dynstr_index = indx;
622     }
623 
624   return true;
625 }
626 
627 /* Mark a symbol dynamic.  */
628 
629 static void
bfd_elf_link_mark_dynamic_symbol(struct bfd_link_info * info,struct elf_link_hash_entry * h,Elf_Internal_Sym * sym)630 bfd_elf_link_mark_dynamic_symbol (struct bfd_link_info *info,
631                                           struct elf_link_hash_entry *h,
632                                           Elf_Internal_Sym *sym)
633 {
634   struct bfd_elf_dynamic_list *d = info->dynamic_list;
635 
636   /* It may be called more than once on the same H.  */
637   if(h->dynamic || bfd_link_relocatable (info))
638     return;
639 
640   if ((info->dynamic_data
641        && (h->type == STT_OBJECT
642              || h->type == STT_COMMON
643              || (sym != NULL
644                  && (ELF_ST_TYPE (sym->st_info) == STT_OBJECT
645                        || ELF_ST_TYPE (sym->st_info) == STT_COMMON))))
646       || (d != NULL
647             && h->non_elf
648             && (*d->match) (&d->head, NULL, h->root.root.string)))
649     {
650       h->dynamic = 1;
651       /* NB: If a symbol is made dynamic by --dynamic-list, it has
652            non-IR reference.  */
653       h->root.non_ir_ref_dynamic = 1;
654     }
655 }
656 
657 /* Record an assignment to a symbol made by a linker script.  We need
658    this in case some dynamic object refers to this symbol.  */
659 
660 bool
bfd_elf_record_link_assignment(bfd * output_bfd,struct bfd_link_info * info,const char * name,bool provide,bool hidden)661 bfd_elf_record_link_assignment (bfd *output_bfd,
662                                         struct bfd_link_info *info,
663                                         const char *name,
664                                         bool provide,
665                                         bool hidden)
666 {
667   struct elf_link_hash_entry *h, *hv;
668   struct elf_link_hash_table *htab;
669   const struct elf_backend_data *bed;
670 
671   if (!is_elf_hash_table (info->hash))
672     return true;
673 
674   htab = elf_hash_table (info);
675   h = elf_link_hash_lookup (htab, name, !provide, true, false);
676   if (h == NULL)
677     return provide;
678 
679   if (h->root.type == bfd_link_hash_warning)
680     h = (struct elf_link_hash_entry *) h->root.u.i.link;
681 
682   if (h->versioned == unknown)
683     {
684       /* Set versioned if symbol version is unknown.  */
685       char *version = strrchr (name, ELF_VER_CHR);
686       if (version)
687           {
688             if (version > name && version[-1] != ELF_VER_CHR)
689               h->versioned = versioned_hidden;
690             else
691               h->versioned = versioned;
692           }
693     }
694 
695   /* Symbols defined in a linker script but not referenced anywhere
696      else will have non_elf set.  */
697   if (h->non_elf)
698     {
699       bfd_elf_link_mark_dynamic_symbol (info, h, NULL);
700       h->non_elf = 0;
701     }
702 
703   switch (h->root.type)
704     {
705     case bfd_link_hash_defined:
706     case bfd_link_hash_defweak:
707     case bfd_link_hash_common:
708       break;
709     case bfd_link_hash_undefweak:
710     case bfd_link_hash_undefined:
711       /* Since we're defining the symbol, don't let it seem to have not
712            been defined.  record_dynamic_symbol and size_dynamic_sections
713            may depend on this.  */
714       h->root.type = bfd_link_hash_new;
715       if (h->root.u.undef.next != NULL || htab->root.undefs_tail == &h->root)
716           bfd_link_repair_undef_list (&htab->root);
717       break;
718     case bfd_link_hash_new:
719       break;
720     case bfd_link_hash_indirect:
721       /* We had a versioned symbol in a dynamic library.  We make the
722            the versioned symbol point to this one.  */
723       bed = get_elf_backend_data (output_bfd);
724       hv = h;
725       while (hv->root.type == bfd_link_hash_indirect
726                || hv->root.type == bfd_link_hash_warning)
727           hv = (struct elf_link_hash_entry *) hv->root.u.i.link;
728       /* We don't need to update h->root.u since linker will set them
729            later.  */
730       h->root.type = bfd_link_hash_undefined;
731       hv->root.type = bfd_link_hash_indirect;
732       hv->root.u.i.link = (struct bfd_link_hash_entry *) h;
733       (*bed->elf_backend_copy_indirect_symbol) (info, h, hv);
734       break;
735     default:
736       BFD_FAIL ();
737       return false;
738     }
739 
740   /* If this symbol is being provided by the linker script, and it is
741      currently defined by a dynamic object, but not by a regular
742      object, then mark it as undefined so that the generic linker will
743      force the correct value.  */
744   if (provide
745       && h->def_dynamic
746       && !h->def_regular)
747     h->root.type = bfd_link_hash_undefined;
748 
749   /* If this symbol is currently defined by a dynamic object, but not
750      by a regular object, then clear out any version information because
751      the symbol will not be associated with the dynamic object any
752      more.  */
753   if (h->def_dynamic && !h->def_regular)
754     h->verinfo.verdef = NULL;
755 
756   /* Make sure this symbol is not garbage collected.  */
757   h->mark = 1;
758 
759   h->def_regular = 1;
760 
761   if (hidden)
762     {
763       bed = get_elf_backend_data (output_bfd);
764       if (ELF_ST_VISIBILITY (h->other) != STV_INTERNAL)
765           h->other = (h->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN;
766       (*bed->elf_backend_hide_symbol) (info, h, true);
767     }
768 
769   /* STV_HIDDEN and STV_INTERNAL symbols must be STB_LOCAL in shared objects
770      and executables.  */
771   if (!bfd_link_relocatable (info)
772       && h->dynindx != -1
773       && (ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
774             || ELF_ST_VISIBILITY (h->other) == STV_INTERNAL))
775     h->forced_local = 1;
776 
777   if ((h->def_dynamic
778        || h->ref_dynamic
779        || bfd_link_dll (info))
780       && !h->forced_local
781       && h->dynindx == -1)
782     {
783       if (! bfd_elf_link_record_dynamic_symbol (info, h))
784           return false;
785 
786       /* If this is a weak defined symbol, and we know a corresponding
787            real symbol from the same dynamic object, make sure the real
788            symbol is also made into a dynamic symbol.  */
789       if (h->is_weakalias)
790           {
791             struct elf_link_hash_entry *def = weakdef (h);
792 
793             if (def->dynindx == -1
794                 && !bfd_elf_link_record_dynamic_symbol (info, def))
795               return false;
796           }
797     }
798 
799   return true;
800 }
801 
802 /* Record a new local dynamic symbol.  Returns 0 on failure, 1 on
803    success, and 2 on a failure caused by attempting to record a symbol
804    in a discarded section, eg. a discarded link-once section symbol.  */
805 
806 int
bfd_elf_link_record_local_dynamic_symbol(struct bfd_link_info * info,bfd * input_bfd,long input_indx)807 bfd_elf_link_record_local_dynamic_symbol (struct bfd_link_info *info,
808                                                     bfd *input_bfd,
809                                                     long input_indx)
810 {
811   size_t amt;
812   struct elf_link_local_dynamic_entry *entry;
813   struct elf_link_hash_table *eht;
814   struct elf_strtab_hash *dynstr;
815   size_t dynstr_index;
816   char *name;
817   Elf_External_Sym_Shndx eshndx;
818   char esym[sizeof (Elf64_External_Sym)];
819 
820   if (! is_elf_hash_table (info->hash))
821     return 0;
822 
823   /* See if the entry exists already.  */
824   for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
825     if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
826       return 1;
827 
828   amt = sizeof (*entry);
829   entry = (struct elf_link_local_dynamic_entry *) bfd_alloc (input_bfd, amt);
830   if (entry == NULL)
831     return 0;
832 
833   /* Go find the symbol, so that we can find it's name.  */
834   if (!bfd_elf_get_elf_syms (input_bfd, &elf_tdata (input_bfd)->symtab_hdr,
835                                    1, input_indx, &entry->isym, esym, &eshndx))
836     {
837       bfd_release (input_bfd, entry);
838       return 0;
839     }
840 
841   if (entry->isym.st_shndx != SHN_UNDEF
842       && entry->isym.st_shndx < SHN_LORESERVE)
843     {
844       asection *s;
845 
846       s = bfd_section_from_elf_index (input_bfd, entry->isym.st_shndx);
847       if (s == NULL || bfd_is_abs_section (s->output_section))
848           {
849             /* We can still bfd_release here as nothing has done another
850                bfd_alloc.  We can't do this later in this function.  */
851             bfd_release (input_bfd, entry);
852             return 2;
853           }
854     }
855 
856   name = (bfd_elf_string_from_elf_section
857             (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
858              entry->isym.st_name));
859 
860   dynstr = elf_hash_table (info)->dynstr;
861   if (dynstr == NULL)
862     {
863       /* Create a strtab to hold the dynamic symbol names.  */
864       elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init ();
865       if (dynstr == NULL)
866           return 0;
867     }
868 
869   dynstr_index = _bfd_elf_strtab_add (dynstr, name, false);
870   if (dynstr_index == (size_t) -1)
871     return 0;
872   entry->isym.st_name = dynstr_index;
873 
874   eht = elf_hash_table (info);
875 
876   entry->next = eht->dynlocal;
877   eht->dynlocal = entry;
878   entry->input_bfd = input_bfd;
879   entry->input_indx = input_indx;
880   eht->dynsymcount++;
881 
882   /* Whatever binding the symbol had before, it's now local.  */
883   entry->isym.st_info
884     = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
885 
886   /* The dynindx will be set at the end of size_dynamic_sections.  */
887 
888   return 1;
889 }
890 
891 /* Return the dynindex of a local dynamic symbol.  */
892 
893 long
_bfd_elf_link_lookup_local_dynindx(struct bfd_link_info * info,bfd * input_bfd,long input_indx)894 _bfd_elf_link_lookup_local_dynindx (struct bfd_link_info *info,
895                                             bfd *input_bfd,
896                                             long input_indx)
897 {
898   struct elf_link_local_dynamic_entry *e;
899 
900   for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
901     if (e->input_bfd == input_bfd && e->input_indx == input_indx)
902       return e->dynindx;
903   return -1;
904 }
905 
906 /* This function is used to renumber the dynamic symbols, if some of
907    them are removed because they are marked as local.  This is called
908    via elf_link_hash_traverse.  */
909 
910 static bool
elf_link_renumber_hash_table_dynsyms(struct elf_link_hash_entry * h,void * data)911 elf_link_renumber_hash_table_dynsyms (struct elf_link_hash_entry *h,
912                                               void *data)
913 {
914   size_t *count = (size_t *) data;
915 
916   if (h->forced_local)
917     return true;
918 
919   if (h->dynindx != -1)
920     h->dynindx = ++(*count);
921 
922   return true;
923 }
924 
925 
926 /* Like elf_link_renumber_hash_table_dynsyms, but just number symbols with
927    STB_LOCAL binding.  */
928 
929 static bool
elf_link_renumber_local_hash_table_dynsyms(struct elf_link_hash_entry * h,void * data)930 elf_link_renumber_local_hash_table_dynsyms (struct elf_link_hash_entry *h,
931                                                       void *data)
932 {
933   size_t *count = (size_t *) data;
934 
935   if (!h->forced_local)
936     return true;
937 
938   if (h->dynindx != -1)
939     h->dynindx = ++(*count);
940 
941   return true;
942 }
943 
944 /* Return true if the dynamic symbol for a given section should be
945    omitted when creating a shared library.  */
946 bool
_bfd_elf_omit_section_dynsym_default(bfd * output_bfd ATTRIBUTE_UNUSED,struct bfd_link_info * info,asection * p)947 _bfd_elf_omit_section_dynsym_default (bfd *output_bfd ATTRIBUTE_UNUSED,
948                                               struct bfd_link_info *info,
949                                               asection *p)
950 {
951   struct elf_link_hash_table *htab;
952   asection *ip;
953 
954   switch (elf_section_data (p)->this_hdr.sh_type)
955     {
956     case SHT_PROGBITS:
957     case SHT_NOBITS:
958       /* If sh_type is yet undecided, assume it could be
959            SHT_PROGBITS/SHT_NOBITS.  */
960     case SHT_NULL:
961       htab = elf_hash_table (info);
962       if (htab->text_index_section != NULL)
963           return p != htab->text_index_section && p != htab->data_index_section;
964 
965       return (htab->dynobj != NULL
966                 && (ip = bfd_get_linker_section (htab->dynobj, p->name)) != NULL
967                 && ip->output_section == p);
968 
969       /* There shouldn't be section relative relocations
970            against any other section.  */
971     default:
972       return true;
973     }
974 }
975 
976 bool
_bfd_elf_omit_section_dynsym_all(bfd * output_bfd ATTRIBUTE_UNUSED,struct bfd_link_info * info ATTRIBUTE_UNUSED,asection * p ATTRIBUTE_UNUSED)977 _bfd_elf_omit_section_dynsym_all
978     (bfd *output_bfd ATTRIBUTE_UNUSED,
979      struct bfd_link_info *info ATTRIBUTE_UNUSED,
980      asection *p ATTRIBUTE_UNUSED)
981 {
982   return true;
983 }
984 
985 /* Assign dynsym indices.  In a shared library we generate a section
986    symbol for each output section, which come first.  Next come symbols
987    which have been forced to local binding.  Then all of the back-end
988    allocated local dynamic syms, followed by the rest of the global
989    symbols.  If SECTION_SYM_COUNT is NULL, section dynindx is not set.
990    (This prevents the early call before elf_backend_init_index_section
991    and strip_excluded_output_sections setting dynindx for sections
992    that are stripped.)  */
993 
994 static unsigned long
_bfd_elf_link_renumber_dynsyms(bfd * output_bfd,struct bfd_link_info * info,unsigned long * section_sym_count)995 _bfd_elf_link_renumber_dynsyms (bfd *output_bfd,
996                                         struct bfd_link_info *info,
997                                         unsigned long *section_sym_count)
998 {
999   unsigned long dynsymcount = 0;
1000   bool do_sec = section_sym_count != NULL;
1001 
1002   if (bfd_link_pic (info)
1003       || elf_hash_table (info)->is_relocatable_executable)
1004     {
1005       const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
1006       asection *p;
1007       for (p = output_bfd->sections; p ; p = p->next)
1008           if ((p->flags & SEC_EXCLUDE) == 0
1009               && (p->flags & SEC_ALLOC) != 0
1010               && elf_hash_table (info)->dynamic_relocs
1011               && !(*bed->elf_backend_omit_section_dynsym) (output_bfd, info, p))
1012             {
1013               ++dynsymcount;
1014               if (do_sec)
1015                 elf_section_data (p)->dynindx = dynsymcount;
1016             }
1017           else if (do_sec)
1018             elf_section_data (p)->dynindx = 0;
1019     }
1020   if (do_sec)
1021     *section_sym_count = dynsymcount;
1022 
1023   elf_link_hash_traverse (elf_hash_table (info),
1024                                 elf_link_renumber_local_hash_table_dynsyms,
1025                                 &dynsymcount);
1026 
1027   if (elf_hash_table (info)->dynlocal)
1028     {
1029       struct elf_link_local_dynamic_entry *p;
1030       for (p = elf_hash_table (info)->dynlocal; p ; p = p->next)
1031           p->dynindx = ++dynsymcount;
1032     }
1033   elf_hash_table (info)->local_dynsymcount = dynsymcount;
1034 
1035   elf_link_hash_traverse (elf_hash_table (info),
1036                                 elf_link_renumber_hash_table_dynsyms,
1037                                 &dynsymcount);
1038 
1039   /* There is an unused NULL entry at the head of the table which we
1040      must account for in our count even if the table is empty since it
1041      is intended for the mandatory DT_SYMTAB tag (.dynsym section) in
1042      .dynamic section.  */
1043   dynsymcount++;
1044 
1045   elf_hash_table (info)->dynsymcount = dynsymcount;
1046   return dynsymcount;
1047 }
1048 
1049 /* Merge st_other field.  */
1050 
1051 static void
elf_merge_st_other(bfd * abfd,struct elf_link_hash_entry * h,unsigned int st_other,asection * sec,bool definition,bool dynamic)1052 elf_merge_st_other (bfd *abfd, struct elf_link_hash_entry *h,
1053                         unsigned int st_other, asection *sec,
1054                         bool definition, bool dynamic)
1055 {
1056   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
1057 
1058   /* If st_other has a processor-specific meaning, specific
1059      code might be needed here.  */
1060   if (bed->elf_backend_merge_symbol_attribute)
1061     (*bed->elf_backend_merge_symbol_attribute) (h, st_other, definition,
1062                                                             dynamic);
1063 
1064   if (!dynamic)
1065     {
1066       unsigned symvis = ELF_ST_VISIBILITY (st_other);
1067       unsigned hvis = ELF_ST_VISIBILITY (h->other);
1068 
1069       /* Keep the most constraining visibility.  Leave the remainder
1070            of the st_other field to elf_backend_merge_symbol_attribute.  */
1071       if (symvis - 1 < hvis - 1)
1072           h->other = symvis | (h->other & ~ELF_ST_VISIBILITY (-1));
1073     }
1074   else if (definition
1075              && ELF_ST_VISIBILITY (st_other) != STV_DEFAULT
1076              && (sec->flags & SEC_READONLY) == 0)
1077     h->protected_def = 1;
1078 }
1079 
1080 /* This function is called when we want to merge a new symbol with an
1081    existing symbol.  It handles the various cases which arise when we
1082    find a definition in a dynamic object, or when there is already a
1083    definition in a dynamic object.  The new symbol is described by
1084    NAME, SYM, PSEC, and PVALUE.  We set SYM_HASH to the hash table
1085    entry.  We set POLDBFD to the old symbol's BFD.  We set POLD_WEAK
1086    if the old symbol was weak.  We set POLD_ALIGNMENT to the alignment
1087    of an old common symbol.  We set OVERRIDE if the old symbol is
1088    overriding a new definition.  We set TYPE_CHANGE_OK if it is OK for
1089    the type to change.  We set SIZE_CHANGE_OK if it is OK for the size
1090    to change.  By OK to change, we mean that we shouldn't warn if the
1091    type or size does change.  */
1092 
1093 static bool
_bfd_elf_merge_symbol(bfd * abfd,struct bfd_link_info * info,const char * name,Elf_Internal_Sym * sym,asection ** psec,bfd_vma * pvalue,struct elf_link_hash_entry ** sym_hash,bfd ** poldbfd,bool * pold_weak,unsigned int * pold_alignment,bool * skip,bfd ** override,bool * type_change_ok,bool * size_change_ok,bool * matched)1094 _bfd_elf_merge_symbol (bfd *abfd,
1095                            struct bfd_link_info *info,
1096                            const char *name,
1097                            Elf_Internal_Sym *sym,
1098                            asection **psec,
1099                            bfd_vma *pvalue,
1100                            struct elf_link_hash_entry **sym_hash,
1101                            bfd **poldbfd,
1102                            bool *pold_weak,
1103                            unsigned int *pold_alignment,
1104                            bool *skip,
1105                            bfd **override,
1106                            bool *type_change_ok,
1107                            bool *size_change_ok,
1108                            bool *matched)
1109 {
1110   asection *sec, *oldsec;
1111   struct elf_link_hash_entry *h;
1112   struct elf_link_hash_entry *hi;
1113   struct elf_link_hash_entry *flip;
1114   int bind;
1115   bfd *oldbfd;
1116   bool newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
1117   bool newweak, oldweak, newfunc, oldfunc;
1118   const struct elf_backend_data *bed;
1119   char *new_version;
1120   bool default_sym = *matched;
1121   struct elf_link_hash_table *htab;
1122 
1123   *skip = false;
1124   *override = NULL;
1125 
1126   sec = *psec;
1127   bind = ELF_ST_BIND (sym->st_info);
1128 
1129   if (! bfd_is_und_section (sec))
1130     h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false);
1131   else
1132     h = ((struct elf_link_hash_entry *)
1133            bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false));
1134   if (h == NULL)
1135     return false;
1136   *sym_hash = h;
1137 
1138   bed = get_elf_backend_data (abfd);
1139 
1140   /* NEW_VERSION is the symbol version of the new symbol.  */
1141   if (h->versioned != unversioned)
1142     {
1143       /* Symbol version is unknown or versioned.  */
1144       new_version = strrchr (name, ELF_VER_CHR);
1145       if (new_version)
1146           {
1147             if (h->versioned == unknown)
1148               {
1149                 if (new_version > name && new_version[-1] != ELF_VER_CHR)
1150                     h->versioned = versioned_hidden;
1151                 else
1152                     h->versioned = versioned;
1153               }
1154             new_version += 1;
1155             if (new_version[0] == '\0')
1156               new_version = NULL;
1157           }
1158       else
1159           h->versioned = unversioned;
1160     }
1161   else
1162     new_version = NULL;
1163 
1164   /* For merging, we only care about real symbols.  But we need to make
1165      sure that indirect symbol dynamic flags are updated.  */
1166   hi = h;
1167   while (h->root.type == bfd_link_hash_indirect
1168            || h->root.type == bfd_link_hash_warning)
1169     h = (struct elf_link_hash_entry *) h->root.u.i.link;
1170 
1171   if (!*matched)
1172     {
1173       if (hi == h || h->root.type == bfd_link_hash_new)
1174           *matched = true;
1175       else
1176           {
1177             /* OLD_HIDDEN is true if the existing symbol is only visible
1178                to the symbol with the same symbol version.  NEW_HIDDEN is
1179                true if the new symbol is only visible to the symbol with
1180                the same symbol version.  */
1181             bool old_hidden = h->versioned == versioned_hidden;
1182             bool new_hidden = hi->versioned == versioned_hidden;
1183             if (!old_hidden && !new_hidden)
1184               /* The new symbol matches the existing symbol if both
1185                  aren't hidden.  */
1186               *matched = true;
1187             else
1188               {
1189                 /* OLD_VERSION is the symbol version of the existing
1190                      symbol. */
1191                 char *old_version;
1192 
1193                 if (h->versioned >= versioned)
1194                     old_version = strrchr (h->root.root.string,
1195                                                ELF_VER_CHR) + 1;
1196                 else
1197                      old_version = NULL;
1198 
1199                 /* The new symbol matches the existing symbol if they
1200                      have the same symbol version.  */
1201                 *matched = (old_version == new_version
1202                                 || (old_version != NULL
1203                                     && new_version != NULL
1204                                     && strcmp (old_version, new_version) == 0));
1205               }
1206           }
1207     }
1208 
1209   /* OLDBFD and OLDSEC are a BFD and an ASECTION associated with the
1210      existing symbol.  */
1211 
1212   oldbfd = NULL;
1213   oldsec = NULL;
1214   switch (h->root.type)
1215     {
1216     default:
1217       break;
1218 
1219     case bfd_link_hash_undefined:
1220     case bfd_link_hash_undefweak:
1221       oldbfd = h->root.u.undef.abfd;
1222       break;
1223 
1224     case bfd_link_hash_defined:
1225     case bfd_link_hash_defweak:
1226       oldbfd = h->root.u.def.section->owner;
1227       oldsec = h->root.u.def.section;
1228       break;
1229 
1230     case bfd_link_hash_common:
1231       oldbfd = h->root.u.c.p->section->owner;
1232       oldsec = h->root.u.c.p->section;
1233       if (pold_alignment)
1234           *pold_alignment = h->root.u.c.p->alignment_power;
1235       break;
1236     }
1237   if (poldbfd && *poldbfd == NULL)
1238     *poldbfd = oldbfd;
1239 
1240   /* Differentiate strong and weak symbols.  */
1241   newweak = bind == STB_WEAK;
1242   oldweak = (h->root.type == bfd_link_hash_defweak
1243                || h->root.type == bfd_link_hash_undefweak);
1244   if (pold_weak)
1245     *pold_weak = oldweak;
1246 
1247   /* We have to check it for every instance since the first few may be
1248      references and not all compilers emit symbol type for undefined
1249      symbols.  */
1250   bfd_elf_link_mark_dynamic_symbol (info, h, sym);
1251 
1252   htab = elf_hash_table (info);
1253 
1254   /* NEWDYN and OLDDYN indicate whether the new or old symbol,
1255      respectively, is from a dynamic object.  */
1256 
1257   newdyn = (abfd->flags & DYNAMIC) != 0;
1258 
1259   /* ref_dynamic_nonweak and dynamic_def flags track actual undefined
1260      syms and defined syms in dynamic libraries respectively.
1261      ref_dynamic on the other hand can be set for a symbol defined in
1262      a dynamic library, and def_dynamic may not be set;  When the
1263      definition in a dynamic lib is overridden by a definition in the
1264      executable use of the symbol in the dynamic lib becomes a
1265      reference to the executable symbol.  */
1266   if (newdyn)
1267     {
1268       if (bfd_is_und_section (sec))
1269           {
1270             if (bind != STB_WEAK)
1271               {
1272                 h->ref_dynamic_nonweak = 1;
1273                 hi->ref_dynamic_nonweak = 1;
1274               }
1275           }
1276       else
1277           {
1278             /* Update the existing symbol only if they match. */
1279             if (*matched)
1280               h->dynamic_def = 1;
1281             hi->dynamic_def = 1;
1282           }
1283     }
1284 
1285   /* If we just created the symbol, mark it as being an ELF symbol.
1286      Other than that, there is nothing to do--there is no merge issue
1287      with a newly defined symbol--so we just return.  */
1288 
1289   if (h->root.type == bfd_link_hash_new)
1290     {
1291       h->non_elf = 0;
1292       return true;
1293     }
1294 
1295   /* In cases involving weak versioned symbols, we may wind up trying
1296      to merge a symbol with itself.  Catch that here, to avoid the
1297      confusion that results if we try to override a symbol with
1298      itself.  The additional tests catch cases like
1299      _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a
1300      dynamic object, which we do want to handle here.  */
1301   if (abfd == oldbfd
1302       && (newweak || oldweak)
1303       && ((abfd->flags & DYNAMIC) == 0
1304             || !h->def_regular))
1305     return true;
1306 
1307   olddyn = false;
1308   if (oldbfd != NULL)
1309     olddyn = (oldbfd->flags & DYNAMIC) != 0;
1310   else if (oldsec != NULL)
1311     {
1312       /* This handles the special SHN_MIPS_{TEXT,DATA} section
1313            indices used by MIPS ELF.  */
1314       olddyn = (oldsec->symbol->flags & BSF_DYNAMIC) != 0;
1315     }
1316 
1317   /* Set non_ir_ref_dynamic only when not handling DT_NEEDED entries.  */
1318   if (!htab->handling_dt_needed
1319       && oldbfd != NULL
1320       && (oldbfd->flags & BFD_PLUGIN) != (abfd->flags & BFD_PLUGIN))
1321     {
1322       if (newdyn != olddyn)
1323           {
1324             /* Handle a case where plugin_notice won't be called and thus
1325                won't set the non_ir_ref flags on the first pass over
1326                symbols.  */
1327             h->root.non_ir_ref_dynamic = true;
1328             hi->root.non_ir_ref_dynamic = true;
1329           }
1330       else if ((oldbfd->flags & BFD_PLUGIN) != 0
1331                  && hi->root.type == bfd_link_hash_indirect)
1332           {
1333             /* Change indirect symbol from IR to undefined.  */
1334             hi->root.type = bfd_link_hash_undefined;
1335             hi->root.u.undef.abfd = oldbfd;
1336           }
1337     }
1338 
1339   /* NEWDEF and OLDDEF indicate whether the new or old symbol,
1340      respectively, appear to be a definition rather than reference.  */
1341 
1342   newdef = !bfd_is_und_section (sec) && !bfd_is_com_section (sec);
1343 
1344   olddef = (h->root.type != bfd_link_hash_undefined
1345               && h->root.type != bfd_link_hash_undefweak
1346               && h->root.type != bfd_link_hash_common);
1347 
1348   /* NEWFUNC and OLDFUNC indicate whether the new or old symbol,
1349      respectively, appear to be a function.  */
1350 
1351   newfunc = (ELF_ST_TYPE (sym->st_info) != STT_NOTYPE
1352                && bed->is_function_type (ELF_ST_TYPE (sym->st_info)));
1353 
1354   oldfunc = (h->type != STT_NOTYPE
1355                && bed->is_function_type (h->type));
1356 
1357   if (!(newfunc && oldfunc)
1358       && ELF_ST_TYPE (sym->st_info) != h->type
1359       && ELF_ST_TYPE (sym->st_info) != STT_NOTYPE
1360       && h->type != STT_NOTYPE
1361       && (newdef || bfd_is_com_section (sec))
1362       && (olddef || h->root.type == bfd_link_hash_common))
1363     {
1364       /* If creating a default indirect symbol ("foo" or "foo@") from
1365            a dynamic versioned definition ("foo@@") skip doing so if
1366            there is an existing regular definition with a different
1367            type.  We don't want, for example, a "time" variable in the
1368            executable overriding a "time" function in a shared library.  */
1369       if (newdyn
1370             && !olddyn)
1371           {
1372             *skip = true;
1373             return true;
1374           }
1375 
1376       /* When adding a symbol from a regular object file after we have
1377            created indirect symbols, undo the indirection and any
1378            dynamic state.  */
1379       if (hi != h
1380             && !newdyn
1381             && olddyn)
1382           {
1383             h = hi;
1384             (*bed->elf_backend_hide_symbol) (info, h, true);
1385             h->forced_local = 0;
1386             h->ref_dynamic = 0;
1387             h->def_dynamic = 0;
1388             h->dynamic_def = 0;
1389             if (h->root.u.undef.next || info->hash->undefs_tail == &h->root)
1390               {
1391                 h->root.type = bfd_link_hash_undefined;
1392                 h->root.u.undef.abfd = abfd;
1393               }
1394             else
1395               {
1396                 h->root.type = bfd_link_hash_new;
1397                 h->root.u.undef.abfd = NULL;
1398               }
1399             return true;
1400           }
1401     }
1402 
1403   /* Check TLS symbols.  We don't check undefined symbols introduced
1404      by "ld -u" which have no type (and oldbfd NULL), and we don't
1405      check symbols from plugins because they also have no type.  */
1406   if (oldbfd != NULL
1407       && (oldbfd->flags & BFD_PLUGIN) == 0
1408       && (abfd->flags & BFD_PLUGIN) == 0
1409       && ELF_ST_TYPE (sym->st_info) != h->type
1410       && (ELF_ST_TYPE (sym->st_info) == STT_TLS || h->type == STT_TLS))
1411     {
1412       bfd *ntbfd, *tbfd;
1413       bool ntdef, tdef;
1414       asection *ntsec, *tsec;
1415 
1416       if (h->type == STT_TLS)
1417           {
1418             ntbfd = abfd;
1419             ntsec = sec;
1420             ntdef = newdef;
1421             tbfd = oldbfd;
1422             tsec = oldsec;
1423             tdef = olddef;
1424           }
1425       else
1426           {
1427             ntbfd = oldbfd;
1428             ntsec = oldsec;
1429             ntdef = olddef;
1430             tbfd = abfd;
1431             tsec = sec;
1432             tdef = newdef;
1433           }
1434 
1435       if (tdef && ntdef)
1436           _bfd_error_handler
1437             /* xgettext:c-format */
1438             (_("%s: TLS definition in %pB section %pA "
1439                "mismatches non-TLS definition in %pB section %pA"),
1440              h->root.root.string, tbfd, tsec, ntbfd, ntsec);
1441       else if (!tdef && !ntdef)
1442           _bfd_error_handler
1443             /* xgettext:c-format */
1444             (_("%s: TLS reference in %pB "
1445                "mismatches non-TLS reference in %pB"),
1446              h->root.root.string, tbfd, ntbfd);
1447       else if (tdef)
1448           _bfd_error_handler
1449             /* xgettext:c-format */
1450             (_("%s: TLS definition in %pB section %pA "
1451                "mismatches non-TLS reference in %pB"),
1452              h->root.root.string, tbfd, tsec, ntbfd);
1453       else
1454           _bfd_error_handler
1455             /* xgettext:c-format */
1456             (_("%s: TLS reference in %pB "
1457                "mismatches non-TLS definition in %pB section %pA"),
1458              h->root.root.string, tbfd, ntbfd, ntsec);
1459 
1460       bfd_set_error (bfd_error_bad_value);
1461       return false;
1462     }
1463 
1464   /* If the old symbol has non-default visibility, we ignore the new
1465      definition from a dynamic object.  */
1466   if (newdyn
1467       && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1468       && !bfd_is_und_section (sec))
1469     {
1470       *skip = true;
1471       /* Make sure this symbol is dynamic.  */
1472       h->ref_dynamic = 1;
1473       hi->ref_dynamic = 1;
1474       /* A protected symbol has external availability. Make sure it is
1475            recorded as dynamic.
1476 
1477            FIXME: Should we check type and size for protected symbol?  */
1478       if (ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
1479           return bfd_elf_link_record_dynamic_symbol (info, h);
1480       else
1481           return true;
1482     }
1483   else if (!newdyn
1484              && ELF_ST_VISIBILITY (sym->st_other) != STV_DEFAULT
1485              && h->def_dynamic)
1486     {
1487       /* If the new symbol with non-default visibility comes from a
1488            relocatable file and the old definition comes from a dynamic
1489            object, we remove the old definition.  */
1490       if (hi->root.type == bfd_link_hash_indirect)
1491           {
1492             /* Handle the case where the old dynamic definition is
1493                default versioned.  We need to copy the symbol info from
1494                the symbol with default version to the normal one if it
1495                was referenced before.  */
1496             if (h->ref_regular)
1497               {
1498                 hi->root.type = h->root.type;
1499                 h->root.type = bfd_link_hash_indirect;
1500                 (*bed->elf_backend_copy_indirect_symbol) (info, hi, h);
1501 
1502                 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1503                 if (ELF_ST_VISIBILITY (sym->st_other) != STV_PROTECTED)
1504                     {
1505                       /* If the new symbol is hidden or internal, completely undo
1506                          any dynamic link state.  */
1507                       (*bed->elf_backend_hide_symbol) (info, h, true);
1508                       h->forced_local = 0;
1509                       h->ref_dynamic = 0;
1510                     }
1511                 else
1512                     h->ref_dynamic = 1;
1513 
1514                 h->def_dynamic = 0;
1515                 /* FIXME: Should we check type and size for protected symbol?  */
1516                 h->size = 0;
1517                 h->type = 0;
1518 
1519                 h = hi;
1520               }
1521             else
1522               h = hi;
1523           }
1524 
1525       /* If the old symbol was undefined before, then it will still be
1526            on the undefs list.  If the new symbol is undefined or
1527            common, we can't make it bfd_link_hash_new here, because new
1528            undefined or common symbols will be added to the undefs list
1529            by _bfd_generic_link_add_one_symbol.  Symbols may not be
1530            added twice to the undefs list.  Also, if the new symbol is
1531            undefweak then we don't want to lose the strong undef.  */
1532       if (h->root.u.undef.next || info->hash->undefs_tail == &h->root)
1533           {
1534             h->root.type = bfd_link_hash_undefined;
1535             h->root.u.undef.abfd = abfd;
1536           }
1537       else
1538           {
1539             h->root.type = bfd_link_hash_new;
1540             h->root.u.undef.abfd = NULL;
1541           }
1542 
1543       if (ELF_ST_VISIBILITY (sym->st_other) != STV_PROTECTED)
1544           {
1545             /* If the new symbol is hidden or internal, completely undo
1546                any dynamic link state.  */
1547             (*bed->elf_backend_hide_symbol) (info, h, true);
1548             h->forced_local = 0;
1549             h->ref_dynamic = 0;
1550           }
1551       else
1552           h->ref_dynamic = 1;
1553       h->def_dynamic = 0;
1554       /* FIXME: Should we check type and size for protected symbol?  */
1555       h->size = 0;
1556       h->type = 0;
1557       return true;
1558     }
1559 
1560   /* If a new weak symbol definition comes from a regular file and the
1561      old symbol comes from a dynamic library, we treat the new one as
1562      strong.  Similarly, an old weak symbol definition from a regular
1563      file is treated as strong when the new symbol comes from a dynamic
1564      library.  Further, an old weak symbol from a dynamic library is
1565      treated as strong if the new symbol is from a dynamic library.
1566      This reflects the way glibc's ld.so works.
1567 
1568      Also allow a weak symbol to override a linker script symbol
1569      defined by an early pass over the script.  This is done so the
1570      linker knows the symbol is defined in an object file, for the
1571      DEFINED script function.
1572 
1573      Do this before setting *type_change_ok or *size_change_ok so that
1574      we warn properly when dynamic library symbols are overridden.  */
1575 
1576   if (newdef && !newdyn && (olddyn || h->root.ldscript_def))
1577     newweak = false;
1578   if (olddef && newdyn)
1579     oldweak = false;
1580 
1581   /* Allow changes between different types of function symbol.  */
1582   if (newfunc && oldfunc)
1583     *type_change_ok = true;
1584 
1585   /* It's OK to change the type if either the existing symbol or the
1586      new symbol is weak.  A type change is also OK if the old symbol
1587      is undefined and the new symbol is defined.  */
1588 
1589   if (oldweak
1590       || newweak
1591       || (newdef
1592             && h->root.type == bfd_link_hash_undefined))
1593     *type_change_ok = true;
1594 
1595   /* It's OK to change the size if either the existing symbol or the
1596      new symbol is weak, or if the old symbol is undefined.  */
1597 
1598   if (*type_change_ok
1599       || h->root.type == bfd_link_hash_undefined)
1600     *size_change_ok = true;
1601 
1602   /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
1603      symbol, respectively, appears to be a common symbol in a dynamic
1604      object.  If a symbol appears in an uninitialized section, and is
1605      not weak, and is not a function, then it may be a common symbol
1606      which was resolved when the dynamic object was created.  We want
1607      to treat such symbols specially, because they raise special
1608      considerations when setting the symbol size: if the symbol
1609      appears as a common symbol in a regular object, and the size in
1610      the regular object is larger, we must make sure that we use the
1611      larger size.  This problematic case can always be avoided in C,
1612      but it must be handled correctly when using Fortran shared
1613      libraries.
1614 
1615      Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
1616      likewise for OLDDYNCOMMON and OLDDEF.
1617 
1618      Note that this test is just a heuristic, and that it is quite
1619      possible to have an uninitialized symbol in a shared object which
1620      is really a definition, rather than a common symbol.  This could
1621      lead to some minor confusion when the symbol really is a common
1622      symbol in some regular object.  However, I think it will be
1623      harmless.  */
1624 
1625   if (newdyn
1626       && newdef
1627       && !newweak
1628       && (sec->flags & SEC_ALLOC) != 0
1629       && (sec->flags & SEC_LOAD) == 0
1630       && sym->st_size > 0
1631       && !newfunc)
1632     newdyncommon = true;
1633   else
1634     newdyncommon = false;
1635 
1636   if (olddyn
1637       && olddef
1638       && h->root.type == bfd_link_hash_defined
1639       && h->def_dynamic
1640       && (h->root.u.def.section->flags & SEC_ALLOC) != 0
1641       && (h->root.u.def.section->flags & SEC_LOAD) == 0
1642       && h->size > 0
1643       && !oldfunc)
1644     olddyncommon = true;
1645   else
1646     olddyncommon = false;
1647 
1648   /* We now know everything about the old and new symbols.  We ask the
1649      backend to check if we can merge them.  */
1650   if (bed->merge_symbol != NULL)
1651     {
1652       if (!bed->merge_symbol (h, sym, psec, newdef, olddef, oldbfd, oldsec))
1653           return false;
1654       sec = *psec;
1655     }
1656 
1657   /* There are multiple definitions of a normal symbol.  Skip the
1658      default symbol as well as definition from an IR object.  */
1659   if (olddef && !olddyn && !oldweak && newdef && !newdyn && !newweak
1660       && !default_sym && h->def_regular
1661       && !(oldbfd != NULL
1662              && (oldbfd->flags & BFD_PLUGIN) != 0
1663              && (abfd->flags & BFD_PLUGIN) == 0))
1664     {
1665       /* Handle a multiple definition.  */
1666       (*info->callbacks->multiple_definition) (info, &h->root,
1667                                                          abfd, sec, *pvalue);
1668       *skip = true;
1669       return true;
1670     }
1671 
1672   /* If both the old and the new symbols look like common symbols in a
1673      dynamic object, set the size of the symbol to the larger of the
1674      two.  */
1675 
1676   if (olddyncommon
1677       && newdyncommon
1678       && sym->st_size != h->size)
1679     {
1680       /* Since we think we have two common symbols, issue a multiple
1681            common warning if desired.  Note that we only warn if the
1682            size is different.  If the size is the same, we simply let
1683            the old symbol override the new one as normally happens with
1684            symbols defined in dynamic objects.  */
1685 
1686       (*info->callbacks->multiple_common) (info, &h->root, abfd,
1687                                                      bfd_link_hash_common, sym->st_size);
1688       if (sym->st_size > h->size)
1689           h->size = sym->st_size;
1690 
1691       *size_change_ok = true;
1692     }
1693 
1694   /* If we are looking at a dynamic object, and we have found a
1695      definition, we need to see if the symbol was already defined by
1696      some other object.  If so, we want to use the existing
1697      definition, and we do not want to report a multiple symbol
1698      definition error; we do this by clobbering *PSEC to be
1699      bfd_und_section_ptr.
1700 
1701      We treat a common symbol as a definition if the symbol in the
1702      shared library is a function, since common symbols always
1703      represent variables; this can cause confusion in principle, but
1704      any such confusion would seem to indicate an erroneous program or
1705      shared library.  We also permit a common symbol in a regular
1706      object to override a weak symbol in a shared object.  */
1707 
1708   if (newdyn
1709       && newdef
1710       && (olddef
1711             || (h->root.type == bfd_link_hash_common
1712                 && (newweak || newfunc))))
1713     {
1714       *override = abfd;
1715       newdef = false;
1716       newdyncommon = false;
1717 
1718       *psec = sec = bfd_und_section_ptr;
1719       *size_change_ok = true;
1720 
1721       /* If we get here when the old symbol is a common symbol, then
1722            we are explicitly letting it override a weak symbol or
1723            function in a dynamic object, and we don't want to warn about
1724            a type change.  If the old symbol is a defined symbol, a type
1725            change warning may still be appropriate.  */
1726 
1727       if (h->root.type == bfd_link_hash_common)
1728           *type_change_ok = true;
1729     }
1730 
1731   /* Handle the special case of an old common symbol merging with a
1732      new symbol which looks like a common symbol in a shared object.
1733      We change *PSEC and *PVALUE to make the new symbol look like a
1734      common symbol, and let _bfd_generic_link_add_one_symbol do the
1735      right thing.  */
1736 
1737   if (newdyncommon
1738       && h->root.type == bfd_link_hash_common)
1739     {
1740       *override = oldbfd;
1741       newdef = false;
1742       newdyncommon = false;
1743       *pvalue = sym->st_size;
1744       *psec = sec = bed->common_section (oldsec);
1745       *size_change_ok = true;
1746     }
1747 
1748   /* Skip weak definitions of symbols that are already defined.  */
1749   if (newdef && olddef && newweak)
1750     {
1751       /* Don't skip new non-IR weak syms.  */
1752       if (!(oldbfd != NULL
1753               && (oldbfd->flags & BFD_PLUGIN) != 0
1754               && (abfd->flags & BFD_PLUGIN) == 0))
1755           {
1756             newdef = false;
1757             *skip = true;
1758           }
1759 
1760       /* Merge st_other.  If the symbol already has a dynamic index,
1761            but visibility says it should not be visible, turn it into a
1762            local symbol.  */
1763       elf_merge_st_other (abfd, h, sym->st_other, sec, newdef, newdyn);
1764       if (h->dynindx != -1)
1765           switch (ELF_ST_VISIBILITY (h->other))
1766             {
1767             case STV_INTERNAL:
1768             case STV_HIDDEN:
1769               (*bed->elf_backend_hide_symbol) (info, h, true);
1770               break;
1771             }
1772     }
1773 
1774   /* If the old symbol is from a dynamic object, and the new symbol is
1775      a definition which is not from a dynamic object, then the new
1776      symbol overrides the old symbol.  Symbols from regular files
1777      always take precedence over symbols from dynamic objects, even if
1778      they are defined after the dynamic object in the link.
1779 
1780      As above, we again permit a common symbol in a regular object to
1781      override a definition in a shared object if the shared object
1782      symbol is a function or is weak.  */
1783 
1784   flip = NULL;
1785   if (!newdyn
1786       && (newdef
1787             || (bfd_is_com_section (sec)
1788                 && (oldweak || oldfunc)))
1789       && olddyn
1790       && olddef
1791       && h->def_dynamic)
1792     {
1793       /* Change the hash table entry to undefined, and let
1794            _bfd_generic_link_add_one_symbol do the right thing with the
1795            new definition.  */
1796 
1797       h->root.type = bfd_link_hash_undefined;
1798       h->root.u.undef.abfd = h->root.u.def.section->owner;
1799       *size_change_ok = true;
1800 
1801       olddef = false;
1802       olddyncommon = false;
1803 
1804       /* We again permit a type change when a common symbol may be
1805            overriding a function.  */
1806 
1807       if (bfd_is_com_section (sec))
1808           {
1809             if (oldfunc)
1810               {
1811                 /* If a common symbol overrides a function, make sure
1812                      that it isn't defined dynamically nor has type
1813                      function.  */
1814                 h->def_dynamic = 0;
1815                 h->type = STT_NOTYPE;
1816               }
1817             *type_change_ok = true;
1818           }
1819 
1820       if (hi->root.type == bfd_link_hash_indirect)
1821           flip = hi;
1822       else
1823           /* This union may have been set to be non-NULL when this symbol
1824              was seen in a dynamic object.  We must force the union to be
1825              NULL, so that it is correct for a regular symbol.  */
1826           h->verinfo.vertree = NULL;
1827     }
1828 
1829   /* Handle the special case of a new common symbol merging with an
1830      old symbol that looks like it might be a common symbol defined in
1831      a shared object.  Note that we have already handled the case in
1832      which a new common symbol should simply override the definition
1833      in the shared library.  */
1834 
1835   if (! newdyn
1836       && bfd_is_com_section (sec)
1837       && olddyncommon)
1838     {
1839       /* It would be best if we could set the hash table entry to a
1840            common symbol, but we don't know what to use for the section
1841            or the alignment.  */
1842       (*info->callbacks->multiple_common) (info, &h->root, abfd,
1843                                                      bfd_link_hash_common, sym->st_size);
1844 
1845       /* If the presumed common symbol in the dynamic object is
1846            larger, pretend that the new symbol has its size.  */
1847 
1848       if (h->size > *pvalue)
1849           *pvalue = h->size;
1850 
1851       /* We need to remember the alignment required by the symbol
1852            in the dynamic object.  */
1853       BFD_ASSERT (pold_alignment);
1854       *pold_alignment = h->root.u.def.section->alignment_power;
1855 
1856       olddef = false;
1857       olddyncommon = false;
1858 
1859       h->root.type = bfd_link_hash_undefined;
1860       h->root.u.undef.abfd = h->root.u.def.section->owner;
1861 
1862       *size_change_ok = true;
1863       *type_change_ok = true;
1864 
1865       if (hi->root.type == bfd_link_hash_indirect)
1866           flip = hi;
1867       else
1868           h->verinfo.vertree = NULL;
1869     }
1870 
1871   if (flip != NULL)
1872     {
1873       /* Handle the case where we had a versioned symbol in a dynamic
1874            library and now find a definition in a normal object.  In this
1875            case, we make the versioned symbol point to the normal one.  */
1876       flip->root.type = h->root.type;
1877       flip->root.u.undef.abfd = h->root.u.undef.abfd;
1878       h->root.type = bfd_link_hash_indirect;
1879       h->root.u.i.link = (struct bfd_link_hash_entry *) flip;
1880       (*bed->elf_backend_copy_indirect_symbol) (info, flip, h);
1881       if (h->def_dynamic)
1882           {
1883             h->def_dynamic = 0;
1884             flip->ref_dynamic = 1;
1885           }
1886     }
1887 
1888   return true;
1889 }
1890 
1891 /* This function is called to create an indirect symbol from the
1892    default for the symbol with the default version if needed. The
1893    symbol is described by H, NAME, SYM, SEC, and VALUE.  We
1894    set DYNSYM if the new indirect symbol is dynamic.  */
1895 
1896 static bool
_bfd_elf_add_default_symbol(bfd * abfd,struct bfd_link_info * info,struct elf_link_hash_entry * h,const char * name,Elf_Internal_Sym * sym,asection * sec,bfd_vma value,bfd ** poldbfd,bool * dynsym)1897 _bfd_elf_add_default_symbol (bfd *abfd,
1898                                    struct bfd_link_info *info,
1899                                    struct elf_link_hash_entry *h,
1900                                    const char *name,
1901                                    Elf_Internal_Sym *sym,
1902                                    asection *sec,
1903                                    bfd_vma value,
1904                                    bfd **poldbfd,
1905                                    bool *dynsym)
1906 {
1907   bool type_change_ok;
1908   bool size_change_ok;
1909   bool skip;
1910   char *shortname;
1911   struct elf_link_hash_entry *hi;
1912   struct bfd_link_hash_entry *bh;
1913   const struct elf_backend_data *bed;
1914   bool collect;
1915   bool dynamic;
1916   bfd *override;
1917   char *p;
1918   size_t len, shortlen;
1919   asection *tmp_sec;
1920   bool matched;
1921 
1922   if (h->versioned == unversioned || h->versioned == versioned_hidden)
1923     return true;
1924 
1925   /* If this symbol has a version, and it is the default version, we
1926      create an indirect symbol from the default name to the fully
1927      decorated name.  This will cause external references which do not
1928      specify a version to be bound to this version of the symbol.  */
1929   p = strchr (name, ELF_VER_CHR);
1930   if (h->versioned == unknown)
1931     {
1932       if (p == NULL)
1933           {
1934             h->versioned = unversioned;
1935             return true;
1936           }
1937       else
1938           {
1939             if (p[1] != ELF_VER_CHR)
1940               {
1941                 h->versioned = versioned_hidden;
1942                 return true;
1943               }
1944             else
1945               h->versioned = versioned;
1946           }
1947     }
1948   else
1949     {
1950       /* PR ld/19073: We may see an unversioned definition after the
1951            default version.  */
1952       if (p == NULL)
1953           return true;
1954     }
1955 
1956   bed = get_elf_backend_data (abfd);
1957   collect = bed->collect;
1958   dynamic = (abfd->flags & DYNAMIC) != 0;
1959 
1960   shortlen = p - name;
1961   shortname = (char *) bfd_hash_allocate (&info->hash->table, shortlen + 1);
1962   if (shortname == NULL)
1963     return false;
1964   memcpy (shortname, name, shortlen);
1965   shortname[shortlen] = '\0';
1966 
1967   /* We are going to create a new symbol.  Merge it with any existing
1968      symbol with this name.  For the purposes of the merge, act as
1969      though we were defining the symbol we just defined, although we
1970      actually going to define an indirect symbol.  */
1971   type_change_ok = false;
1972   size_change_ok = false;
1973   matched = true;
1974   tmp_sec = sec;
1975   if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &tmp_sec, &value,
1976                                     &hi, poldbfd, NULL, NULL, &skip, &override,
1977                                     &type_change_ok, &size_change_ok, &matched))
1978     return false;
1979 
1980   if (skip)
1981     goto nondefault;
1982 
1983   if (hi->def_regular || ELF_COMMON_DEF_P (hi))
1984     {
1985       /* If the undecorated symbol will have a version added by a
1986            script different to H, then don't indirect to/from the
1987            undecorated symbol.  This isn't ideal because we may not yet
1988            have seen symbol versions, if given by a script on the
1989            command line rather than via --version-script.  */
1990       if (hi->verinfo.vertree == NULL && info->version_info != NULL)
1991           {
1992             bool hide;
1993 
1994             hi->verinfo.vertree
1995               = bfd_find_version_for_sym (info->version_info,
1996                                                   hi->root.root.string, &hide);
1997             if (hi->verinfo.vertree != NULL && hide)
1998               {
1999                 (*bed->elf_backend_hide_symbol) (info, hi, true);
2000                 goto nondefault;
2001               }
2002           }
2003       if (hi->verinfo.vertree != NULL
2004             && strcmp (p + 1 + (p[1] == '@'), hi->verinfo.vertree->name) != 0)
2005           goto nondefault;
2006     }
2007 
2008   if (! override)
2009     {
2010       /* Add the default symbol if not performing a relocatable link.  */
2011       if (! bfd_link_relocatable (info))
2012           {
2013             bh = &hi->root;
2014             if (bh->type == bfd_link_hash_defined
2015                 && bh->u.def.section->owner != NULL
2016                 && (bh->u.def.section->owner->flags & BFD_PLUGIN) != 0)
2017               {
2018                 /* Mark the previous definition from IR object as
2019                      undefined so that the generic linker will override
2020                      it.  */
2021                 bh->type = bfd_link_hash_undefined;
2022                 bh->u.undef.abfd = bh->u.def.section->owner;
2023               }
2024             if (! (_bfd_generic_link_add_one_symbol
2025                      (info, abfd, shortname, BSF_INDIRECT,
2026                       bfd_ind_section_ptr,
2027                       0, name, false, collect, &bh)))
2028               return false;
2029             hi = (struct elf_link_hash_entry *) bh;
2030           }
2031     }
2032   else
2033     {
2034       /* In this case the symbol named SHORTNAME is overriding the
2035            indirect symbol we want to add.  We were planning on making
2036            SHORTNAME an indirect symbol referring to NAME.  SHORTNAME
2037            is the name without a version.  NAME is the fully versioned
2038            name, and it is the default version.
2039 
2040            Overriding means that we already saw a definition for the
2041            symbol SHORTNAME in a regular object, and it is overriding
2042            the symbol defined in the dynamic object.
2043 
2044            When this happens, we actually want to change NAME, the
2045            symbol we just added, to refer to SHORTNAME.  This will cause
2046            references to NAME in the shared object to become references
2047            to SHORTNAME in the regular object.  This is what we expect
2048            when we override a function in a shared object: that the
2049            references in the shared object will be mapped to the
2050            definition in the regular object.  */
2051 
2052       while (hi->root.type == bfd_link_hash_indirect
2053                || hi->root.type == bfd_link_hash_warning)
2054           hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
2055 
2056       h->root.type = bfd_link_hash_indirect;
2057       h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
2058       if (h->def_dynamic)
2059           {
2060             h->def_dynamic = 0;
2061             hi->ref_dynamic = 1;
2062             if (hi->ref_regular
2063                 || hi->def_regular)
2064               {
2065                 if (! bfd_elf_link_record_dynamic_symbol (info, hi))
2066                     return false;
2067               }
2068           }
2069 
2070       /* Now set HI to H, so that the following code will set the
2071            other fields correctly.  */
2072       hi = h;
2073     }
2074 
2075   /* Check if HI is a warning symbol.  */
2076   if (hi->root.type == bfd_link_hash_warning)
2077     hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
2078 
2079   /* If there is a duplicate definition somewhere, then HI may not
2080      point to an indirect symbol.  We will have reported an error to
2081      the user in that case.  */
2082 
2083   if (hi->root.type == bfd_link_hash_indirect)
2084     {
2085       struct elf_link_hash_entry *ht;
2086 
2087       ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
2088       (*bed->elf_backend_copy_indirect_symbol) (info, ht, hi);
2089 
2090       /* If we first saw a reference to SHORTNAME with non-default
2091            visibility, merge that visibility to the @@VER symbol.  */
2092       elf_merge_st_other (abfd, ht, hi->other, sec, true, dynamic);
2093 
2094       /* A reference to the SHORTNAME symbol from a dynamic library
2095            will be satisfied by the versioned symbol at runtime.  In
2096            effect, we have a reference to the versioned symbol.  */
2097       ht->ref_dynamic_nonweak |= hi->ref_dynamic_nonweak;
2098       hi->dynamic_def |= ht->dynamic_def;
2099 
2100       /* See if the new flags lead us to realize that the symbol must
2101            be dynamic.  */
2102       if (! *dynsym)
2103           {
2104             if (! dynamic)
2105               {
2106                 if (! bfd_link_executable (info)
2107                       || hi->def_dynamic
2108                       || hi->ref_dynamic)
2109                     *dynsym = true;
2110               }
2111             else
2112               {
2113                 if (hi->ref_regular)
2114                     *dynsym = true;
2115               }
2116           }
2117     }
2118 
2119   /* We also need to define an indirection from the nondefault version
2120      of the symbol.  */
2121 
2122  nondefault:
2123   len = strlen (name);
2124   shortname = (char *) bfd_hash_allocate (&info->hash->table, len);
2125   if (shortname == NULL)
2126     return false;
2127   memcpy (shortname, name, shortlen);
2128   memcpy (shortname + shortlen, p + 1, len - shortlen);
2129 
2130   /* Once again, merge with any existing symbol.  */
2131   type_change_ok = false;
2132   size_change_ok = false;
2133   tmp_sec = sec;
2134   if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &tmp_sec, &value,
2135                                     &hi, poldbfd, NULL, NULL, &skip, &override,
2136                                     &type_change_ok, &size_change_ok, &matched))
2137     return false;
2138 
2139   if (skip)
2140     {
2141       if (!dynamic
2142             && h->root.type == bfd_link_hash_defweak
2143             && hi->root.type == bfd_link_hash_defined)
2144           {
2145             /* We are handling a weak sym@@ver and attempting to define
2146                a weak sym@ver, but _bfd_elf_merge_symbol said to skip the
2147                new weak sym@ver because there is already a strong sym@ver.
2148                However, sym@ver and sym@@ver are really the same symbol.
2149                The existing strong sym@ver ought to override sym@@ver.  */
2150             h->root.type = bfd_link_hash_defined;
2151             h->root.u.def.section = hi->root.u.def.section;
2152             h->root.u.def.value = hi->root.u.def.value;
2153             hi->root.type = bfd_link_hash_indirect;
2154             hi->root.u.i.link = &h->root;
2155           }
2156       else
2157           return true;
2158     }
2159   else if (override)
2160     {
2161       /* Here SHORTNAME is a versioned name, so we don't expect to see
2162            the type of override we do in the case above unless it is
2163            overridden by a versioned definition.  */
2164       if (hi->root.type != bfd_link_hash_defined
2165             && hi->root.type != bfd_link_hash_defweak)
2166           _bfd_error_handler
2167             /* xgettext:c-format */
2168             (_("%pB: unexpected redefinition of indirect versioned symbol `%s'"),
2169              abfd, shortname);
2170       return true;
2171     }
2172   else
2173     {
2174       bh = &hi->root;
2175       if (! (_bfd_generic_link_add_one_symbol
2176                (info, abfd, shortname, BSF_INDIRECT,
2177                 bfd_ind_section_ptr, 0, name, false, collect, &bh)))
2178           return false;
2179       hi = (struct elf_link_hash_entry *) bh;
2180     }
2181 
2182   /* If there is a duplicate definition somewhere, then HI may not
2183      point to an indirect symbol.  We will have reported an error
2184      to the user in that case.  */
2185   if (hi->root.type == bfd_link_hash_indirect)
2186     {
2187       (*bed->elf_backend_copy_indirect_symbol) (info, h, hi);
2188       h->ref_dynamic_nonweak |= hi->ref_dynamic_nonweak;
2189       hi->dynamic_def |= h->dynamic_def;
2190 
2191       /* If we first saw a reference to @VER symbol with
2192            non-default visibility, merge that visibility to the
2193            @@VER symbol.  */
2194       elf_merge_st_other (abfd, h, hi->other, sec, true, dynamic);
2195 
2196       /* See if the new flags lead us to realize that the symbol
2197            must be dynamic.  */
2198       if (! *dynsym)
2199           {
2200             if (! dynamic)
2201               {
2202                 if (! bfd_link_executable (info)
2203                       || hi->ref_dynamic)
2204                     *dynsym = true;
2205               }
2206             else
2207               {
2208                 if (hi->ref_regular)
2209                     *dynsym = true;
2210               }
2211           }
2212     }
2213 
2214   return true;
2215 }
2216 
2217 /* This routine is used to export all defined symbols into the dynamic
2218    symbol table.  It is called via elf_link_hash_traverse.  */
2219 
2220 static bool
_bfd_elf_export_symbol(struct elf_link_hash_entry * h,void * data)2221 _bfd_elf_export_symbol (struct elf_link_hash_entry *h, void *data)
2222 {
2223   struct elf_info_failed *eif = (struct elf_info_failed *) data;
2224 
2225   /* Ignore indirect symbols.  These are added by the versioning code.  */
2226   if (h->root.type == bfd_link_hash_indirect)
2227     return true;
2228 
2229   /* Ignore this if we won't export it.  */
2230   if (!eif->info->export_dynamic && !h->dynamic)
2231     return true;
2232 
2233   if (h->dynindx == -1
2234       && (h->def_regular || h->ref_regular)
2235       && ! bfd_hide_sym_by_version (eif->info->version_info,
2236                                             h->root.root.string))
2237     {
2238       if (! bfd_elf_link_record_dynamic_symbol (eif->info, h))
2239           {
2240             eif->failed = true;
2241             return false;
2242           }
2243     }
2244 
2245   return true;
2246 }
2247 
2248 /* Return the glibc version reference if VERSION_DEP is added to the
2249    list of glibc version dependencies successfully.  VERSION_DEP will
2250    be put into the .gnu.version_r section.  */
2251 
2252 static Elf_Internal_Verneed *
elf_link_add_glibc_verneed(struct elf_find_verdep_info * rinfo,Elf_Internal_Verneed * glibc_verref,const char * version_dep)2253 elf_link_add_glibc_verneed (struct elf_find_verdep_info *rinfo,
2254                                   Elf_Internal_Verneed *glibc_verref,
2255                                   const char *version_dep)
2256 {
2257   Elf_Internal_Verneed *t;
2258   Elf_Internal_Vernaux *a;
2259   size_t amt;
2260 
2261   if (glibc_verref != NULL)
2262     {
2263       t = glibc_verref;
2264 
2265       for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2266           {
2267             /* Return if VERSION_DEP dependency has been added.  */
2268             if (a->vna_nodename == version_dep
2269                 || strcmp (a->vna_nodename, version_dep) == 0)
2270               return t;
2271           }
2272     }
2273   else
2274     {
2275       bool is_glibc;
2276 
2277       for (t = elf_tdata (rinfo->info->output_bfd)->verref;
2278              t != NULL;
2279              t = t->vn_nextref)
2280           {
2281             const char *soname = bfd_elf_get_dt_soname (t->vn_bfd);
2282             if (soname != NULL && startswith (soname, "libc.so."))
2283               break;
2284           }
2285 
2286       /* Skip the shared library if it isn't libc.so.  */
2287       if (t == NULL)
2288           return t;
2289 
2290       is_glibc = false;
2291       for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2292           {
2293             /* Return if VERSION_DEP dependency has been added.  */
2294             if (a->vna_nodename == version_dep
2295                 || strcmp (a->vna_nodename, version_dep) == 0)
2296               return t;
2297 
2298             /* Check if libc.so provides GLIBC_2.XX version.  */
2299             if (!is_glibc && startswith (a->vna_nodename, "GLIBC_2."))
2300               is_glibc = true;
2301           }
2302 
2303       /* Skip if it isn't linked against glibc.  */
2304       if (!is_glibc)
2305           return NULL;
2306     }
2307 
2308   amt = sizeof *a;
2309   a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->info->output_bfd, amt);
2310   if (a == NULL)
2311     {
2312       rinfo->failed = true;
2313       return NULL;
2314     }
2315 
2316   a->vna_nodename = version_dep;
2317   a->vna_flags = 0;
2318   a->vna_nextptr = t->vn_auxptr;
2319   a->vna_other = rinfo->vers + 1;
2320   ++rinfo->vers;
2321 
2322   t->vn_auxptr = a;
2323 
2324   return t;
2325 }
2326 
2327 /* Add VERSION_DEP to the list of version dependencies when linked
2328    against glibc.  */
2329 
2330 void
_bfd_elf_link_add_glibc_version_dependency(struct elf_find_verdep_info * rinfo,const char * version_dep[])2331 _bfd_elf_link_add_glibc_version_dependency
2332   (struct elf_find_verdep_info *rinfo,
2333    const char *version_dep[])
2334 {
2335   Elf_Internal_Verneed *t = NULL;
2336 
2337   do
2338     {
2339       t = elf_link_add_glibc_verneed (rinfo, t, *version_dep);
2340       /* Return if there is no glibc version reference.  */
2341       if (t == NULL)
2342           return;
2343       version_dep++;
2344     }
2345   while (*version_dep != NULL);
2346 }
2347 
2348 /* Add GLIBC_ABI_DT_RELR to the list of version dependencies when
2349    linked against glibc.  */
2350 
2351 void
_bfd_elf_link_add_dt_relr_dependency(struct elf_find_verdep_info * rinfo)2352 _bfd_elf_link_add_dt_relr_dependency (struct elf_find_verdep_info *rinfo)
2353 {
2354   if (rinfo->info->enable_dt_relr)
2355     {
2356       const char *version[] =
2357           {
2358             "GLIBC_ABI_DT_RELR",
2359             NULL
2360           };
2361       _bfd_elf_link_add_glibc_version_dependency (rinfo, version);
2362     }
2363 }
2364 
2365 /* Look through the symbols which are defined in other shared
2366    libraries and referenced here.  Update the list of version
2367    dependencies.  This will be put into the .gnu.version_r section.
2368    This function is called via elf_link_hash_traverse.  */
2369 
2370 static bool
_bfd_elf_link_find_version_dependencies(struct elf_link_hash_entry * h,void * data)2371 _bfd_elf_link_find_version_dependencies (struct elf_link_hash_entry *h,
2372                                                    void *data)
2373 {
2374   struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
2375   Elf_Internal_Verneed *t;
2376   Elf_Internal_Vernaux *a;
2377   size_t amt;
2378 
2379   /* We only care about symbols defined in shared objects with version
2380      information.  */
2381   if (!h->def_dynamic
2382       || h->def_regular
2383       || h->dynindx == -1
2384       || h->verinfo.verdef == NULL
2385       || (elf_dyn_lib_class (h->verinfo.verdef->vd_bfd)
2386             & (DYN_AS_NEEDED | DYN_DT_NEEDED | DYN_NO_NEEDED)))
2387     return true;
2388 
2389   /* See if we already know about this version.  */
2390   for (t = elf_tdata (rinfo->info->output_bfd)->verref;
2391        t != NULL;
2392        t = t->vn_nextref)
2393     {
2394       if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
2395           continue;
2396 
2397       for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2398           if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
2399             return true;
2400 
2401       break;
2402     }
2403 
2404   /* This is a new version.  Add it to tree we are building.  */
2405 
2406   if (t == NULL)
2407     {
2408       amt = sizeof *t;
2409       t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->info->output_bfd, amt);
2410       if (t == NULL)
2411           {
2412             rinfo->failed = true;
2413             return false;
2414           }
2415 
2416       t->vn_bfd = h->verinfo.verdef->vd_bfd;
2417       t->vn_nextref = elf_tdata (rinfo->info->output_bfd)->verref;
2418       elf_tdata (rinfo->info->output_bfd)->verref = t;
2419     }
2420 
2421   amt = sizeof *a;
2422   a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->info->output_bfd, amt);
2423   if (a == NULL)
2424     {
2425       rinfo->failed = true;
2426       return false;
2427     }
2428 
2429   /* Note that we are copying a string pointer here, and testing it
2430      above.  If bfd_elf_string_from_elf_section is ever changed to
2431      discard the string data when low in memory, this will have to be
2432      fixed.  */
2433   a->vna_nodename = h->verinfo.verdef->vd_nodename;
2434 
2435   a->vna_flags = h->verinfo.verdef->vd_flags;
2436   a->vna_nextptr = t->vn_auxptr;
2437 
2438   h->verinfo.verdef->vd_exp_refno = rinfo->vers;
2439   ++rinfo->vers;
2440 
2441   a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
2442 
2443   t->vn_auxptr = a;
2444 
2445   return true;
2446 }
2447 
2448 /* Return TRUE and set *HIDE to TRUE if the versioned symbol is
2449    hidden.  Set *T_P to NULL if there is no match.  */
2450 
2451 static bool
_bfd_elf_link_hide_versioned_symbol(struct bfd_link_info * info,struct elf_link_hash_entry * h,const char * version_p,struct bfd_elf_version_tree ** t_p,bool * hide)2452 _bfd_elf_link_hide_versioned_symbol (struct bfd_link_info *info,
2453                                              struct elf_link_hash_entry *h,
2454                                              const char *version_p,
2455                                              struct bfd_elf_version_tree **t_p,
2456                                              bool *hide)
2457 {
2458   struct bfd_elf_version_tree *t;
2459 
2460   /* Look for the version.  If we find it, it is no longer weak.  */
2461   for (t = info->version_info; t != NULL; t = t->next)
2462     {
2463       if (strcmp (t->name, version_p) == 0)
2464           {
2465             size_t len;
2466             char *alc;
2467             struct bfd_elf_version_expr *d;
2468 
2469             len = version_p - h->root.root.string;
2470             alc = (char *) bfd_malloc (len);
2471             if (alc == NULL)
2472               return false;
2473             memcpy (alc, h->root.root.string, len - 1);
2474             alc[len - 1] = '\0';
2475             if (alc[len - 2] == ELF_VER_CHR)
2476               alc[len - 2] = '\0';
2477 
2478             h->verinfo.vertree = t;
2479             t->used = true;
2480             d = NULL;
2481 
2482             if (t->globals.list != NULL)
2483               d = (*t->match) (&t->globals, NULL, alc);
2484 
2485             /* See if there is anything to force this symbol to
2486                local scope.  */
2487             if (d == NULL && t->locals.list != NULL)
2488               {
2489                 d = (*t->match) (&t->locals, NULL, alc);
2490                 if (d != NULL
2491                       && h->dynindx != -1
2492                       && ! info->export_dynamic)
2493                     *hide = true;
2494               }
2495 
2496             free (alc);
2497             break;
2498           }
2499     }
2500 
2501   *t_p = t;
2502 
2503   return true;
2504 }
2505 
2506 /* Return TRUE if the symbol H is hidden by version script.  */
2507 
2508 bool
_bfd_elf_link_hide_sym_by_version(struct bfd_link_info * info,struct elf_link_hash_entry * h)2509 _bfd_elf_link_hide_sym_by_version (struct bfd_link_info *info,
2510                                            struct elf_link_hash_entry *h)
2511 {
2512   const char *p;
2513   bool hide = false;
2514   const struct elf_backend_data *bed
2515     = get_elf_backend_data (info->output_bfd);
2516 
2517   /* Version script only hides symbols defined in regular objects.  */
2518   if (!h->def_regular && !ELF_COMMON_DEF_P (h))
2519     return true;
2520 
2521   p = strchr (h->root.root.string, ELF_VER_CHR);
2522   if (p != NULL && h->verinfo.vertree == NULL)
2523     {
2524       struct bfd_elf_version_tree *t;
2525 
2526       ++p;
2527       if (*p == ELF_VER_CHR)
2528           ++p;
2529 
2530       if (*p != '\0'
2531             && _bfd_elf_link_hide_versioned_symbol (info, h, p, &t, &hide)
2532             && hide)
2533           {
2534             if (hide)
2535               (*bed->elf_backend_hide_symbol) (info, h, true);
2536             return true;
2537           }
2538     }
2539 
2540   /* If we don't have a version for this symbol, see if we can find
2541      something.  */
2542   if (h->verinfo.vertree == NULL && info->version_info != NULL)
2543     {
2544       h->verinfo.vertree
2545           = bfd_find_version_for_sym (info->version_info,
2546                                             h->root.root.string, &hide);
2547       if (h->verinfo.vertree != NULL && hide)
2548           {
2549             (*bed->elf_backend_hide_symbol) (info, h, true);
2550             return true;
2551           }
2552     }
2553 
2554   return false;
2555 }
2556 
2557 /* Figure out appropriate versions for all the symbols.  We may not
2558    have the version number script until we have read all of the input
2559    files, so until that point we don't know which symbols should be
2560    local.  This function is called via elf_link_hash_traverse.  */
2561 
2562 static bool
_bfd_elf_link_assign_sym_version(struct elf_link_hash_entry * h,void * data)2563 _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
2564 {
2565   struct elf_info_failed *sinfo;
2566   struct bfd_link_info *info;
2567   const struct elf_backend_data *bed;
2568   struct elf_info_failed eif;
2569   char *p;
2570   bool hide;
2571 
2572   sinfo = (struct elf_info_failed *) data;
2573   info = sinfo->info;
2574 
2575   /* Fix the symbol flags.  */
2576   eif.failed = false;
2577   eif.info = info;
2578   if (! _bfd_elf_fix_symbol_flags (h, &eif))
2579     {
2580       if (eif.failed)
2581           sinfo->failed = true;
2582       return false;
2583     }
2584 
2585   bed = get_elf_backend_data (info->output_bfd);
2586 
2587   /* We only need version numbers for symbols defined in regular
2588      objects.  */
2589   if (!h->def_regular && !ELF_COMMON_DEF_P (h))
2590     {
2591       /* Hide symbols defined in discarded input sections.  */
2592       if ((h->root.type == bfd_link_hash_defined
2593              || h->root.type == bfd_link_hash_defweak)
2594             && discarded_section (h->root.u.def.section))
2595           (*bed->elf_backend_hide_symbol) (info, h, true);
2596       return true;
2597     }
2598 
2599   hide = false;
2600   p = strchr (h->root.root.string, ELF_VER_CHR);
2601   if (p != NULL && h->verinfo.vertree == NULL)
2602     {
2603       struct bfd_elf_version_tree *t;
2604 
2605       ++p;
2606       if (*p == ELF_VER_CHR)
2607           ++p;
2608 
2609       /* If there is no version string, we can just return out.  */
2610       if (*p == '\0')
2611           return true;
2612 
2613       if (!_bfd_elf_link_hide_versioned_symbol (info, h, p, &t, &hide))
2614           {
2615             sinfo->failed = true;
2616             return false;
2617           }
2618 
2619       if (hide)
2620           (*bed->elf_backend_hide_symbol) (info, h, true);
2621 
2622       /* If we are building an application, we need to create a
2623            version node for this version.  */
2624       if (t == NULL && bfd_link_executable (info))
2625           {
2626             struct bfd_elf_version_tree **pp;
2627             int version_index;
2628 
2629             /* If we aren't going to export this symbol, we don't need
2630                to worry about it.  */
2631             if (h->dynindx == -1)
2632               return true;
2633 
2634             t = (struct bfd_elf_version_tree *) bfd_zalloc (info->output_bfd,
2635                                                                         sizeof *t);
2636             if (t == NULL)
2637               {
2638                 sinfo->failed = true;
2639                 return false;
2640               }
2641 
2642             t->name = p;
2643             t->name_indx = (unsigned int) -1;
2644             t->used = true;
2645 
2646             version_index = 1;
2647             /* Don't count anonymous version tag.  */
2648             if (sinfo->info->version_info != NULL
2649                 && sinfo->info->version_info->vernum == 0)
2650               version_index = 0;
2651             for (pp = &sinfo->info->version_info;
2652                  *pp != NULL;
2653                  pp = &(*pp)->next)
2654               ++version_index;
2655             t->vernum = version_index;
2656 
2657             *pp = t;
2658 
2659             h->verinfo.vertree = t;
2660           }
2661       else if (t == NULL)
2662           {
2663             /* We could not find the version for a symbol when
2664                generating a shared archive.  Return an error.  */
2665             _bfd_error_handler
2666               /* xgettext:c-format */
2667               (_("%pB: version node not found for symbol %s"),
2668                info->output_bfd, h->root.root.string);
2669             bfd_set_error (bfd_error_bad_value);
2670             sinfo->failed = true;
2671             return false;
2672           }
2673     }
2674 
2675   /* If we don't have a version for this symbol, see if we can find
2676      something.  */
2677   if (!hide
2678       && h->verinfo.vertree == NULL
2679       && sinfo->info->version_info != NULL)
2680     {
2681       h->verinfo.vertree
2682           = bfd_find_version_for_sym (sinfo->info->version_info,
2683                                             h->root.root.string, &hide);
2684       if (h->verinfo.vertree != NULL && hide)
2685           (*bed->elf_backend_hide_symbol) (info, h, true);
2686     }
2687 
2688   return true;
2689 }
2690 
2691 /* Read and swap the relocs from the section indicated by SHDR.  This
2692    may be either a REL or a RELA section.  The relocations are
2693    translated into RELA relocations and stored in INTERNAL_RELOCS,
2694    which should have already been allocated to contain enough space.
2695    The *EXTERNAL_RELOCS_P are a buffer where the external form of the
2696    relocations should be stored.  If *EXTERNAL_RELOCS_ADDR is NULL,
2697    *EXTERNAL_RELOCS_ADDR and *EXTERNAL_RELOCS_SIZE returns the mmap
2698    memory address and size.  Otherwise, *EXTERNAL_RELOCS_ADDR is
2699    unchanged and *EXTERNAL_RELOCS_SIZE returns 0.
2700 
2701    Returns FALSE if something goes wrong.  */
2702 
2703 static bool
elf_link_read_relocs_from_section(bfd * abfd,const asection * sec,Elf_Internal_Shdr * shdr,void ** external_relocs_addr,size_t * external_relocs_size,Elf_Internal_Rela * internal_relocs)2704 elf_link_read_relocs_from_section (bfd *abfd,
2705                                            const asection *sec,
2706                                            Elf_Internal_Shdr *shdr,
2707                                            void **external_relocs_addr,
2708                                            size_t *external_relocs_size,
2709                                            Elf_Internal_Rela *internal_relocs)
2710 {
2711   const struct elf_backend_data *bed;
2712   void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
2713   const bfd_byte *erela;
2714   const bfd_byte *erelaend;
2715   Elf_Internal_Rela *irela;
2716   Elf_Internal_Shdr *symtab_hdr;
2717   size_t nsyms;
2718   void *external_relocs = *external_relocs_addr;
2719 
2720   /* Position ourselves at the start of the section.  */
2721   if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2722     return false;
2723 
2724   /* Read the relocations.  */
2725   *external_relocs_size = shdr->sh_size;
2726   if (!_bfd_mmap_read_temporary (&external_relocs,
2727                                          external_relocs_size,
2728                                          external_relocs_addr, abfd, true))
2729     return false;
2730 
2731   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
2732   nsyms = NUM_SHDR_ENTRIES (symtab_hdr);
2733 
2734   bed = get_elf_backend_data (abfd);
2735 
2736   /* Convert the external relocations to the internal format.  */
2737   if (shdr->sh_entsize == bed->s->sizeof_rel)
2738     swap_in = bed->s->swap_reloc_in;
2739   else if (shdr->sh_entsize == bed->s->sizeof_rela)
2740     swap_in = bed->s->swap_reloca_in;
2741   else
2742     {
2743       bfd_set_error (bfd_error_wrong_format);
2744       return false;
2745     }
2746 
2747   erela = (const bfd_byte *) external_relocs;
2748   /* Setting erelaend like this and comparing with <= handles case of
2749      a fuzzed object with sh_size not a multiple of sh_entsize.  */
2750   erelaend = erela + shdr->sh_size - shdr->sh_entsize;
2751   irela = internal_relocs;
2752   while (erela <= erelaend)
2753     {
2754       bfd_vma r_symndx;
2755 
2756       (*swap_in) (abfd, erela, irela);
2757       r_symndx = ELF32_R_SYM (irela->r_info);
2758       if (bed->s->arch_size == 64)
2759           r_symndx >>= 24;
2760       if (nsyms > 0)
2761           {
2762             if ((size_t) r_symndx >= nsyms)
2763               {
2764                 _bfd_error_handler
2765                     /* xgettext:c-format */
2766                     (_("%pB: bad reloc symbol index (%#" PRIx64 " >= %#lx)"
2767                        " for offset %#" PRIx64 " in section `%pA'"),
2768                      abfd, (uint64_t) r_symndx, (unsigned long) nsyms,
2769                      (uint64_t) irela->r_offset, sec);
2770                 bfd_set_error (bfd_error_bad_value);
2771                 return false;
2772               }
2773           }
2774       else if (r_symndx != STN_UNDEF)
2775           {
2776             _bfd_error_handler
2777               /* xgettext:c-format */
2778               (_("%pB: non-zero symbol index (%#" PRIx64 ")"
2779                  " for offset %#" PRIx64 " in section `%pA'"
2780                  " when the object file has no symbol table"),
2781                abfd, (uint64_t) r_symndx,
2782                (uint64_t) irela->r_offset, sec);
2783             bfd_set_error (bfd_error_bad_value);
2784             return false;
2785           }
2786       irela += bed->s->int_rels_per_ext_rel;
2787       erela += shdr->sh_entsize;
2788     }
2789 
2790   return true;
2791 }
2792 
2793 /* Read and swap the relocs for a section O.  They may have been
2794    cached.  If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
2795    not NULL, they are used as buffers to read into.  They are known to
2796    be large enough.  If the INTERNAL_RELOCS relocs argument is NULL,
2797    the return value is allocated using either malloc or bfd_alloc,
2798    according to the KEEP_MEMORY argument.  If O has two relocation
2799    sections (both REL and RELA relocations), then the REL_HDR
2800    relocations will appear first in INTERNAL_RELOCS, followed by the
2801    RELA_HDR relocations.  If INFO isn't NULL and KEEP_MEMORY is true,
2802    update cache_size.  */
2803 
2804 Elf_Internal_Rela *
_bfd_elf_link_info_read_relocs(bfd * abfd,struct bfd_link_info * info,const asection * o,void * external_relocs,Elf_Internal_Rela * internal_relocs,bool keep_memory)2805 _bfd_elf_link_info_read_relocs (bfd *abfd,
2806                                         struct bfd_link_info *info,
2807                                         const asection *o,
2808                                         void *external_relocs,
2809                                         Elf_Internal_Rela *internal_relocs,
2810                                         bool keep_memory)
2811 {
2812   void *alloc1 = NULL;
2813   size_t alloc1_size;
2814   Elf_Internal_Rela *alloc2 = NULL;
2815   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
2816   struct bfd_elf_section_data *esdo = elf_section_data (o);
2817   Elf_Internal_Rela *internal_rela_relocs;
2818 
2819   if (esdo->relocs != NULL)
2820     return esdo->relocs;
2821 
2822   if (o->reloc_count == 0)
2823     return NULL;
2824 
2825   if (internal_relocs == NULL)
2826     {
2827       bfd_size_type size;
2828 
2829       size = (bfd_size_type) o->reloc_count * sizeof (Elf_Internal_Rela);
2830       if (keep_memory)
2831           {
2832             internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2833             if (info)
2834               info->cache_size += size;
2835           }
2836       else
2837           internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2838       if (internal_relocs == NULL)
2839           return NULL;
2840     }
2841 
2842   alloc1 = external_relocs;
2843   internal_rela_relocs = internal_relocs;
2844   if (esdo->rel.hdr)
2845     {
2846       if (!elf_link_read_relocs_from_section (abfd, o, esdo->rel.hdr,
2847                                                         &alloc1, &alloc1_size,
2848                                                         internal_relocs))
2849           goto error_return;
2850       external_relocs = (((bfd_byte *) external_relocs)
2851                                + esdo->rel.hdr->sh_size);
2852       internal_rela_relocs += (NUM_SHDR_ENTRIES (esdo->rel.hdr)
2853                                      * bed->s->int_rels_per_ext_rel);
2854     }
2855 
2856   if (esdo->rela.hdr
2857       && (!elf_link_read_relocs_from_section (abfd, o, esdo->rela.hdr,
2858                                                         &alloc1, &alloc1_size,
2859                                                         internal_rela_relocs)))
2860     goto error_return;
2861 
2862   /* Cache the results for next time, if we can.  */
2863   if (keep_memory)
2864     esdo->relocs = internal_relocs;
2865 
2866   _bfd_munmap_readonly_temporary (alloc1, alloc1_size);
2867 
2868   /* Don't free alloc2, since if it was allocated we are passing it
2869      back (under the name of internal_relocs).  */
2870 
2871   return internal_relocs;
2872 
2873  error_return:
2874   _bfd_munmap_readonly_temporary (alloc1, alloc1_size);
2875   if (alloc2 != NULL)
2876     {
2877       if (keep_memory)
2878           bfd_release (abfd, alloc2);
2879       else
2880           free (alloc2);
2881     }
2882   return NULL;
2883 }
2884 
2885 /* This is similar to _bfd_elf_link_info_read_relocs, except for that
2886    NULL is passed to _bfd_elf_link_info_read_relocs for pointer to
2887    struct bfd_link_info.  */
2888 
2889 Elf_Internal_Rela *
_bfd_elf_link_read_relocs(bfd * abfd,const asection * o,void * external_relocs,Elf_Internal_Rela * internal_relocs,bool keep_memory)2890 _bfd_elf_link_read_relocs (bfd *abfd,
2891                                  const asection *o,
2892                                  void *external_relocs,
2893                                  Elf_Internal_Rela *internal_relocs,
2894                                  bool keep_memory)
2895 {
2896   return _bfd_elf_link_info_read_relocs (abfd, NULL, o, external_relocs,
2897                                                    internal_relocs, keep_memory);
2898 
2899 }
2900 
2901 /* Compute the size of, and allocate space for, REL_HDR which is the
2902    section header for a section containing relocations for O.  */
2903 
2904 static bool
_bfd_elf_link_size_reloc_section(bfd * abfd,struct bfd_elf_section_reloc_data * reldata)2905 _bfd_elf_link_size_reloc_section (bfd *abfd,
2906                                           struct bfd_elf_section_reloc_data *reldata)
2907 {
2908   Elf_Internal_Shdr *rel_hdr = reldata->hdr;
2909 
2910   /* That allows us to calculate the size of the section.  */
2911   rel_hdr->sh_size = rel_hdr->sh_entsize * reldata->count;
2912 
2913   /* The contents field must last into write_object_contents, so we
2914      allocate it with bfd_alloc rather than malloc.  Also since we
2915      cannot be sure that the contents will actually be filled in,
2916      we zero the allocated space.  */
2917   rel_hdr->contents = (unsigned char *) bfd_zalloc (abfd, rel_hdr->sh_size);
2918   if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
2919     return false;
2920 
2921   if (reldata->hashes == NULL && reldata->count)
2922     {
2923       struct elf_link_hash_entry **p;
2924 
2925       p = ((struct elf_link_hash_entry **)
2926              bfd_zmalloc (reldata->count * sizeof (*p)));
2927       if (p == NULL)
2928           return false;
2929 
2930       reldata->hashes = p;
2931     }
2932 
2933   return true;
2934 }
2935 
2936 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
2937    originated from the section given by INPUT_REL_HDR) to the
2938    OUTPUT_BFD.  */
2939 
2940 bool
_bfd_elf_link_output_relocs(bfd * output_bfd,asection * input_section,Elf_Internal_Shdr * input_rel_hdr,Elf_Internal_Rela * internal_relocs,struct elf_link_hash_entry ** rel_hash)2941 _bfd_elf_link_output_relocs (bfd *output_bfd,
2942                                    asection *input_section,
2943                                    Elf_Internal_Shdr *input_rel_hdr,
2944                                    Elf_Internal_Rela *internal_relocs,
2945                                    struct elf_link_hash_entry **rel_hash)
2946 {
2947   Elf_Internal_Rela *irela;
2948   Elf_Internal_Rela *irelaend;
2949   bfd_byte *erel;
2950   struct bfd_elf_section_reloc_data *output_reldata;
2951   asection *output_section;
2952   const struct elf_backend_data *bed;
2953   void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
2954   struct bfd_elf_section_data *esdo;
2955 
2956   output_section = input_section->output_section;
2957 
2958   bed = get_elf_backend_data (output_bfd);
2959   esdo = elf_section_data (output_section);
2960   if (esdo->rel.hdr && esdo->rel.hdr->sh_entsize == input_rel_hdr->sh_entsize)
2961     {
2962       output_reldata = &esdo->rel;
2963       swap_out = bed->s->swap_reloc_out;
2964     }
2965   else if (esdo->rela.hdr
2966              && esdo->rela.hdr->sh_entsize == input_rel_hdr->sh_entsize)
2967     {
2968       output_reldata = &esdo->rela;
2969       swap_out = bed->s->swap_reloca_out;
2970     }
2971   else
2972     {
2973       _bfd_error_handler
2974           /* xgettext:c-format */
2975           (_("%pB: relocation size mismatch in %pB section %pA"),
2976            output_bfd, input_section->owner, input_section);
2977       bfd_set_error (bfd_error_wrong_format);
2978       return false;
2979     }
2980 
2981   erel = output_reldata->hdr->contents;
2982   erel += output_reldata->count * input_rel_hdr->sh_entsize;
2983   irela = internal_relocs;
2984   irelaend = irela + (NUM_SHDR_ENTRIES (input_rel_hdr)
2985                           * bed->s->int_rels_per_ext_rel);
2986   while (irela < irelaend)
2987     {
2988       if (rel_hash && *rel_hash)
2989           (*rel_hash)->has_reloc = 1;
2990       (*swap_out) (output_bfd, irela, erel);
2991       irela += bed->s->int_rels_per_ext_rel;
2992       erel += input_rel_hdr->sh_entsize;
2993       if (rel_hash)
2994           rel_hash++;
2995     }
2996 
2997   /* Bump the counter, so that we know where to add the next set of
2998      relocations.  */
2999   output_reldata->count += NUM_SHDR_ENTRIES (input_rel_hdr);
3000 
3001   return true;
3002 }
3003 
3004 /* Make weak undefined symbols in PIE dynamic.  */
3005 
3006 bool
_bfd_elf_link_hash_fixup_symbol(struct bfd_link_info * info,struct elf_link_hash_entry * h)3007 _bfd_elf_link_hash_fixup_symbol (struct bfd_link_info *info,
3008                                          struct elf_link_hash_entry *h)
3009 {
3010   if (bfd_link_pie (info)
3011       && h->dynindx == -1
3012       && h->root.type == bfd_link_hash_undefweak)
3013     return bfd_elf_link_record_dynamic_symbol (info, h);
3014 
3015   return true;
3016 }
3017 
3018 /* Fix up the flags for a symbol.  This handles various cases which
3019    can only be fixed after all the input files are seen.  This is
3020    currently called by both adjust_dynamic_symbol and
3021    assign_sym_version, which is unnecessary but perhaps more robust in
3022    the face of future changes.  */
3023 
3024 static bool
_bfd_elf_fix_symbol_flags(struct elf_link_hash_entry * h,struct elf_info_failed * eif)3025 _bfd_elf_fix_symbol_flags (struct elf_link_hash_entry *h,
3026                                  struct elf_info_failed *eif)
3027 {
3028   const struct elf_backend_data *bed;
3029 
3030   /* If this symbol was mentioned in a non-ELF file, try to set
3031      DEF_REGULAR and REF_REGULAR correctly.  This is the only way to
3032      permit a non-ELF file to correctly refer to a symbol defined in
3033      an ELF dynamic object.  */
3034   if (h->non_elf)
3035     {
3036       while (h->root.type == bfd_link_hash_indirect)
3037           h = (struct elf_link_hash_entry *) h->root.u.i.link;
3038 
3039       if (h->root.type != bfd_link_hash_defined
3040             && h->root.type != bfd_link_hash_defweak)
3041           {
3042             h->ref_regular = 1;
3043             h->ref_regular_nonweak = 1;
3044           }
3045       else
3046           {
3047             if (h->root.u.def.section->owner != NULL
3048                 && (bfd_get_flavour (h->root.u.def.section->owner)
3049                       == bfd_target_elf_flavour))
3050               {
3051                 h->ref_regular = 1;
3052                 h->ref_regular_nonweak = 1;
3053               }
3054             else
3055               h->def_regular = 1;
3056           }
3057 
3058       if (h->dynindx == -1
3059             && (h->def_dynamic
3060                 || h->ref_dynamic))
3061           {
3062             if (! bfd_elf_link_record_dynamic_symbol (eif->info, h))
3063               {
3064                 eif->failed = true;
3065                 return false;
3066               }
3067           }
3068     }
3069   else
3070     {
3071       /* Unfortunately, NON_ELF is only correct if the symbol
3072            was first seen in a non-ELF file.  Fortunately, if the symbol
3073            was first seen in an ELF file, we're probably OK unless the
3074            symbol was defined in a non-ELF file.  Catch that case here.
3075            FIXME: We're still in trouble if the symbol was first seen in
3076            a dynamic object, and then later in a non-ELF regular object.  */
3077       if ((h->root.type == bfd_link_hash_defined
3078              || h->root.type == bfd_link_hash_defweak)
3079             && !h->def_regular
3080             && (h->root.u.def.section->owner != NULL
3081                 ? (bfd_get_flavour (h->root.u.def.section->owner)
3082                      != bfd_target_elf_flavour)
3083                 : (bfd_is_abs_section (h->root.u.def.section)
3084                      && !h->def_dynamic)))
3085           h->def_regular = 1;
3086     }
3087 
3088   /* Backend specific symbol fixup.  */
3089   bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
3090   if (bed->elf_backend_fixup_symbol
3091       && !(*bed->elf_backend_fixup_symbol) (eif->info, h))
3092     return false;
3093 
3094   /* If this is a final link, and the symbol was defined as a common
3095      symbol in a regular object file, and there was no definition in
3096      any dynamic object, then the linker will have allocated space for
3097      the symbol in a common section but the DEF_REGULAR
3098      flag will not have been set.  */
3099   if (h->root.type == bfd_link_hash_defined
3100       && !h->def_regular
3101       && h->ref_regular
3102       && !h->def_dynamic
3103       && (h->root.u.def.section->owner->flags & (DYNAMIC | BFD_PLUGIN)) == 0)
3104     h->def_regular = 1;
3105 
3106   /* Symbols defined in discarded sections shouldn't be dynamic.  */
3107   if (h->root.type == bfd_link_hash_undefined && h->indx == -3)
3108     (*bed->elf_backend_hide_symbol) (eif->info, h, true);
3109 
3110   /* If a weak undefined symbol has non-default visibility, we also
3111      hide it from the dynamic linker.  */
3112   else if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
3113              && h->root.type == bfd_link_hash_undefweak)
3114     (*bed->elf_backend_hide_symbol) (eif->info, h, true);
3115 
3116   /* A hidden versioned symbol in executable should be forced local if
3117      it is is locally defined, not referenced by shared library and not
3118      exported.  */
3119   else if (bfd_link_executable (eif->info)
3120              && h->versioned == versioned_hidden
3121              && !eif->info->export_dynamic
3122              && !h->dynamic
3123              && !h->ref_dynamic
3124              && h->def_regular)
3125     (*bed->elf_backend_hide_symbol) (eif->info, h, true);
3126 
3127   /* If -Bsymbolic was used (which means to bind references to global
3128      symbols to the definition within the shared object), and this
3129      symbol was defined in a regular object, then it actually doesn't
3130      need a PLT entry.  Likewise, if the symbol has non-default
3131      visibility.  If the symbol has hidden or internal visibility, we
3132      will force it local.  */
3133   else if (h->needs_plt
3134              && bfd_link_pic (eif->info)
3135              && is_elf_hash_table (eif->info->hash)
3136              && (SYMBOLIC_BIND (eif->info, h)
3137                  || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
3138              && h->def_regular)
3139     {
3140       bool force_local;
3141 
3142       force_local = (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
3143                          || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN);
3144       (*bed->elf_backend_hide_symbol) (eif->info, h, force_local);
3145     }
3146 
3147   /* If this is a weak defined symbol in a dynamic object, and we know
3148      the real definition in the dynamic object, copy interesting flags
3149      over to the real definition.  */
3150   if (h->is_weakalias)
3151     {
3152       struct elf_link_hash_entry *def = weakdef (h);
3153 
3154       /* If the real definition is defined by a regular object file,
3155            don't do anything special.  See the longer description in
3156            _bfd_elf_adjust_dynamic_symbol, below.  If the def is not
3157            bfd_link_hash_defined as it was when put on the alias list
3158            then it must have originally been a versioned symbol (for
3159            which a non-versioned indirect symbol is created) and later
3160            a definition for the non-versioned symbol is found.  In that
3161            case the indirection is flipped with the versioned symbol
3162            becoming an indirect pointing at the non-versioned symbol.
3163            Thus, not an alias any more.  */
3164       if (def->def_regular
3165             || def->root.type != bfd_link_hash_defined)
3166           {
3167             h = def;
3168             while ((h = h->u.alias) != def)
3169               h->is_weakalias = 0;
3170           }
3171       else
3172           {
3173             while (h->root.type == bfd_link_hash_indirect)
3174               h = (struct elf_link_hash_entry *) h->root.u.i.link;
3175             BFD_ASSERT (h->root.type == bfd_link_hash_defined
3176                           || h->root.type == bfd_link_hash_defweak);
3177             BFD_ASSERT (def->def_dynamic);
3178             (*bed->elf_backend_copy_indirect_symbol) (eif->info, def, h);
3179           }
3180     }
3181 
3182   return true;
3183 }
3184 
3185 /* Make the backend pick a good value for a dynamic symbol.  This is
3186    called via elf_link_hash_traverse, and also calls itself
3187    recursively.  */
3188 
3189 static bool
_bfd_elf_adjust_dynamic_symbol(struct elf_link_hash_entry * h,void * data)3190 _bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data)
3191 {
3192   struct elf_info_failed *eif = (struct elf_info_failed *) data;
3193   struct elf_link_hash_table *htab;
3194   const struct elf_backend_data *bed;
3195 
3196   if (! is_elf_hash_table (eif->info->hash))
3197     return false;
3198 
3199   /* Ignore indirect symbols.  These are added by the versioning code.  */
3200   if (h->root.type == bfd_link_hash_indirect)
3201     return true;
3202 
3203   /* Fix the symbol flags.  */
3204   if (! _bfd_elf_fix_symbol_flags (h, eif))
3205     return false;
3206 
3207   htab = elf_hash_table (eif->info);
3208   bed = get_elf_backend_data (htab->dynobj);
3209 
3210   if (h->root.type == bfd_link_hash_undefweak)
3211     {
3212       if (eif->info->dynamic_undefined_weak == 0)
3213           (*bed->elf_backend_hide_symbol) (eif->info, h, true);
3214       else if (eif->info->dynamic_undefined_weak > 0
3215                  && h->ref_regular
3216                  && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
3217                  && !bfd_hide_sym_by_version (eif->info->version_info,
3218                                                       h->root.root.string))
3219           {
3220             if (!bfd_elf_link_record_dynamic_symbol (eif->info, h))
3221               {
3222                 eif->failed = true;
3223                 return false;
3224               }
3225           }
3226     }
3227 
3228   /* If this symbol does not require a PLT entry, and it is not
3229      defined by a dynamic object, or is not referenced by a regular
3230      object, ignore it.  We do have to handle a weak defined symbol,
3231      even if no regular object refers to it, if we decided to add it
3232      to the dynamic symbol table.  FIXME: Do we normally need to worry
3233      about symbols which are defined by one dynamic object and
3234      referenced by another one?  */
3235   if (!h->needs_plt
3236       && h->type != STT_GNU_IFUNC
3237       && (h->def_regular
3238             || !h->def_dynamic
3239             || (!h->ref_regular
3240                 && (!h->is_weakalias || weakdef (h)->dynindx == -1))))
3241     {
3242       h->plt = elf_hash_table (eif->info)->init_plt_offset;
3243       return true;
3244     }
3245 
3246   /* If we've already adjusted this symbol, don't do it again.  This
3247      can happen via a recursive call.  */
3248   if (h->dynamic_adjusted)
3249     return true;
3250 
3251   /* Don't look at this symbol again.  Note that we must set this
3252      after checking the above conditions, because we may look at a
3253      symbol once, decide not to do anything, and then get called
3254      recursively later after REF_REGULAR is set below.  */
3255   h->dynamic_adjusted = 1;
3256 
3257   /* If this is a weak definition, and we know a real definition, and
3258      the real symbol is not itself defined by a regular object file,
3259      then get a good value for the real definition.  We handle the
3260      real symbol first, for the convenience of the backend routine.
3261 
3262      Note that there is a confusing case here.  If the real definition
3263      is defined by a regular object file, we don't get the real symbol
3264      from the dynamic object, but we do get the weak symbol.  If the
3265      processor backend uses a COPY reloc, then if some routine in the
3266      dynamic object changes the real symbol, we will not see that
3267      change in the corresponding weak symbol.  This is the way other
3268      ELF linkers work as well, and seems to be a result of the shared
3269      library model.
3270 
3271      I will clarify this issue.  Most SVR4 shared libraries define the
3272      variable _timezone and define timezone as a weak synonym.  The
3273      tzset call changes _timezone.  If you write
3274        extern int timezone;
3275        int _timezone = 5;
3276        int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3277      you might expect that, since timezone is a synonym for _timezone,
3278      the same number will print both times.  However, if the processor
3279      backend uses a COPY reloc, then actually timezone will be copied
3280      into your process image, and, since you define _timezone
3281      yourself, _timezone will not.  Thus timezone and _timezone will
3282      wind up at different memory locations.  The tzset call will set
3283      _timezone, leaving timezone unchanged.  */
3284 
3285   if (h->is_weakalias)
3286     {
3287       struct elf_link_hash_entry *def = weakdef (h);
3288 
3289       /* If we get to this point, there is an implicit reference to
3290            the alias by a regular object file via the weak symbol H.  */
3291       def->ref_regular = 1;
3292 
3293       /* Ensure that the backend adjust_dynamic_symbol function sees
3294            the strong alias before H by recursively calling ourselves.  */
3295       if (!_bfd_elf_adjust_dynamic_symbol (def, eif))
3296           return false;
3297     }
3298 
3299   /* If a symbol has no type and no size and does not require a PLT
3300      entry, then we are probably about to do the wrong thing here: we
3301      are probably going to create a COPY reloc for an empty object.
3302      This case can arise when a shared object is built with assembly
3303      code, and the assembly code fails to set the symbol type.  */
3304   if (h->size == 0
3305       && h->type == STT_NOTYPE
3306       && !h->needs_plt)
3307     _bfd_error_handler
3308       (_("warning: type and size of dynamic symbol `%s' are not defined"),
3309        h->root.root.string);
3310 
3311   if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3312     {
3313       eif->failed = true;
3314       return false;
3315     }
3316 
3317   return true;
3318 }
3319 
3320 /* Adjust the dynamic symbol, H, for copy in the dynamic bss section,
3321    DYNBSS.  */
3322 
3323 bool
_bfd_elf_adjust_dynamic_copy(struct bfd_link_info * info,struct elf_link_hash_entry * h,asection * dynbss)3324 _bfd_elf_adjust_dynamic_copy (struct bfd_link_info *info,
3325                                     struct elf_link_hash_entry *h,
3326                                     asection *dynbss)
3327 {
3328   unsigned int power_of_two;
3329   bfd_vma mask;
3330   asection *sec = h->root.u.def.section;
3331 
3332   /* The section alignment of the definition is the maximum alignment
3333      requirement of symbols defined in the section.  Since we don't
3334      know the symbol alignment requirement, we start with the
3335      maximum alignment and check low bits of the symbol address
3336      for the minimum alignment.  */
3337   power_of_two = bfd_section_alignment (sec);
3338   mask = ((bfd_vma) 1 << power_of_two) - 1;
3339   while ((h->root.u.def.value & mask) != 0)
3340     {
3341        mask >>= 1;
3342        --power_of_two;
3343     }
3344 
3345   if (power_of_two > bfd_section_alignment (dynbss))
3346     {
3347       /* Adjust the section alignment if needed.  */
3348       if (!bfd_set_section_alignment (dynbss, power_of_two))
3349           return false;
3350     }
3351 
3352   /* We make sure that the symbol will be aligned properly.  */
3353   dynbss->size = BFD_ALIGN (dynbss->size, mask + 1);
3354 
3355   /* Define the symbol as being at this point in DYNBSS.  */
3356   h->root.u.def.section = dynbss;
3357   h->root.u.def.value = dynbss->size;
3358 
3359   /* Increment the size of DYNBSS to make room for the symbol.  */
3360   dynbss->size += h->size;
3361 
3362   /* No error if extern_protected_data is true.  */
3363   if (h->protected_def
3364       && (!info->extern_protected_data
3365             || (info->extern_protected_data < 0
3366                 && !get_elf_backend_data (dynbss->owner)->extern_protected_data)))
3367     info->callbacks->einfo
3368       (_("%P: copy reloc against protected `%pT' is dangerous\n"),
3369        h->root.root.string);
3370 
3371   return true;
3372 }
3373 
3374 /* Adjust all external symbols pointing into SEC_MERGE sections
3375    to reflect the object merging within the sections.  */
3376 
3377 static bool
_bfd_elf_link_sec_merge_syms(struct elf_link_hash_entry * h,void * data)3378 _bfd_elf_link_sec_merge_syms (struct elf_link_hash_entry *h, void *data)
3379 {
3380   asection *sec;
3381 
3382   if ((h->root.type == bfd_link_hash_defined
3383        || h->root.type == bfd_link_hash_defweak)
3384       && ((sec = h->root.u.def.section)->flags & SEC_MERGE)
3385       && sec->sec_info_type == SEC_INFO_TYPE_MERGE)
3386     {
3387       bfd *output_bfd = (bfd *) data;
3388 
3389       h->root.u.def.value =
3390           _bfd_merged_section_offset (output_bfd,
3391                                             &h->root.u.def.section,
3392                                             elf_section_data (sec)->sec_info,
3393                                             h->root.u.def.value);
3394     }
3395 
3396   return true;
3397 }
3398 
3399 /* Returns false if the symbol referred to by H should be considered
3400    to resolve local to the current module, and true if it should be
3401    considered to bind dynamically.  */
3402 
3403 bool
_bfd_elf_dynamic_symbol_p(struct elf_link_hash_entry * h,struct bfd_link_info * info,bool not_local_protected)3404 _bfd_elf_dynamic_symbol_p (struct elf_link_hash_entry *h,
3405                                  struct bfd_link_info *info,
3406                                  bool not_local_protected)
3407 {
3408   bool binding_stays_local_p;
3409   const struct elf_backend_data *bed;
3410   struct elf_link_hash_table *hash_table;
3411 
3412   if (h == NULL)
3413     return false;
3414 
3415   while (h->root.type == bfd_link_hash_indirect
3416            || h->root.type == bfd_link_hash_warning)
3417     h = (struct elf_link_hash_entry *) h->root.u.i.link;
3418 
3419   /* If it was forced local, then clearly it's not dynamic.  */
3420   if (h->dynindx == -1)
3421     return false;
3422   if (h->forced_local)
3423     return false;
3424 
3425   /* Identify the cases where name binding rules say that a
3426      visible symbol resolves locally.  */
3427   binding_stays_local_p = (bfd_link_executable (info)
3428                                  || SYMBOLIC_BIND (info, h));
3429 
3430   switch (ELF_ST_VISIBILITY (h->other))
3431     {
3432     case STV_INTERNAL:
3433     case STV_HIDDEN:
3434       return false;
3435 
3436     case STV_PROTECTED:
3437       hash_table = elf_hash_table (info);
3438       if (!is_elf_hash_table (&hash_table->root))
3439           return false;
3440 
3441       bed = get_elf_backend_data (hash_table->dynobj);
3442 
3443       /* Proper resolution for function pointer equality may require
3444            that these symbols perhaps be resolved dynamically, even though
3445            we should be resolving them to the current module.  */
3446       if (!not_local_protected || !bed->is_function_type (h->type))
3447           binding_stays_local_p = true;
3448       break;
3449 
3450     default:
3451       break;
3452     }
3453 
3454   /* If it isn't defined locally, then clearly it's dynamic.  */
3455   if (!h->def_regular && !ELF_COMMON_DEF_P (h))
3456     return true;
3457 
3458   /* Otherwise, the symbol is dynamic if binding rules don't tell
3459      us that it remains local.  */
3460   return !binding_stays_local_p;
3461 }
3462 
3463 /* Return true if the symbol referred to by H should be considered
3464    to resolve local to the current module, and false otherwise.  Differs
3465    from (the inverse of) _bfd_elf_dynamic_symbol_p in the treatment of
3466    undefined symbols.  The two functions are virtually identical except
3467    for the place where dynindx == -1 is tested.  If that test is true,
3468    _bfd_elf_dynamic_symbol_p will say the symbol is local, while
3469    _bfd_elf_symbol_refs_local_p will say the symbol is local only for
3470    defined symbols.
3471    It might seem that _bfd_elf_dynamic_symbol_p could be rewritten as
3472    !_bfd_elf_symbol_refs_local_p, except that targets differ in their
3473    treatment of undefined weak symbols.  For those that do not make
3474    undefined weak symbols dynamic, both functions may return false.  */
3475 
3476 bool
_bfd_elf_symbol_refs_local_p(struct elf_link_hash_entry * h,struct bfd_link_info * info,bool local_protected)3477 _bfd_elf_symbol_refs_local_p (struct elf_link_hash_entry *h,
3478                                     struct bfd_link_info *info,
3479                                     bool local_protected)
3480 {
3481   const struct elf_backend_data *bed;
3482   struct elf_link_hash_table *hash_table;
3483 
3484   /* If it's a local sym, of course we resolve locally.  */
3485   if (h == NULL)
3486     return true;
3487 
3488   /* STV_HIDDEN or STV_INTERNAL ones must be local.  */
3489   if (ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
3490       || ELF_ST_VISIBILITY (h->other) == STV_INTERNAL)
3491     return true;
3492 
3493   /* Forced local symbols resolve locally.  */
3494   if (h->forced_local)
3495     return true;
3496 
3497   /* Common symbols that become definitions don't get the DEF_REGULAR
3498      flag set, so test it first, and don't bail out.  */
3499   if (ELF_COMMON_DEF_P (h))
3500     /* Do nothing.  */;
3501   /* If we don't have a definition in a regular file, then we can't
3502      resolve locally.  The sym is either undefined or dynamic.  */
3503   else if (!h->def_regular)
3504     return false;
3505 
3506   /* Non-dynamic symbols resolve locally.  */
3507   if (h->dynindx == -1)
3508     return true;
3509 
3510   /* At this point, we know the symbol is defined and dynamic.  In an
3511      executable it must resolve locally, likewise when building symbolic
3512      shared libraries.  */
3513   if (bfd_link_executable (info) || SYMBOLIC_BIND (info, h))
3514     return true;
3515 
3516   /* Now deal with defined dynamic symbols in shared libraries.  Ones
3517      with default visibility might not resolve locally.  */
3518   if (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
3519     return false;
3520 
3521   hash_table = elf_hash_table (info);
3522   if (!is_elf_hash_table (&hash_table->root))
3523     return true;
3524 
3525   /* STV_PROTECTED symbols with indirect external access are local. */
3526   if (info->indirect_extern_access > 0)
3527     return true;
3528 
3529   bed = get_elf_backend_data (hash_table->dynobj);
3530 
3531   /* If extern_protected_data is false, STV_PROTECTED non-function
3532      symbols are local.  */
3533   if ((!info->extern_protected_data
3534        || (info->extern_protected_data < 0
3535              && !bed->extern_protected_data))
3536       && !bed->is_function_type (h->type))
3537     return true;
3538 
3539   /* Function pointer equality tests may require that STV_PROTECTED
3540      symbols be treated as dynamic symbols.  If the address of a
3541      function not defined in an executable is set to that function's
3542      plt entry in the executable, then the address of the function in
3543      a shared library must also be the plt entry in the executable.  */
3544   return local_protected;
3545 }
3546 
3547 /* Caches some TLS segment info, and ensures that the TLS segment vma is
3548    aligned.  Returns the first TLS output section.  */
3549 
3550 struct bfd_section *
_bfd_elf_tls_setup(bfd * obfd,struct bfd_link_info * info)3551 _bfd_elf_tls_setup (bfd *obfd, struct bfd_link_info *info)
3552 {
3553   struct bfd_section *sec, *tls;
3554   unsigned int align = 0;
3555 
3556   for (sec = obfd->sections; sec != NULL; sec = sec->next)
3557     if ((sec->flags & SEC_THREAD_LOCAL) != 0)
3558       break;
3559   tls = sec;
3560 
3561   for (; sec != NULL && (sec->flags & SEC_THREAD_LOCAL) != 0; sec = sec->next)
3562     if (sec->alignment_power > align)
3563       align = sec->alignment_power;
3564 
3565   elf_hash_table (info)->tls_sec = tls;
3566 
3567   /* Ensure the alignment of the first section (usually .tdata) is the largest
3568      alignment, so that the tls segment starts aligned.  */
3569   if (tls != NULL)
3570     tls->alignment_power = align;
3571 
3572   return tls;
3573 }
3574 
3575 /* Return TRUE iff this is a non-common, definition of a non-function symbol.  */
3576 static bool
is_global_data_symbol_definition(bfd * abfd ATTRIBUTE_UNUSED,Elf_Internal_Sym * sym)3577 is_global_data_symbol_definition (bfd *abfd ATTRIBUTE_UNUSED,
3578                                           Elf_Internal_Sym *sym)
3579 {
3580   const struct elf_backend_data *bed;
3581 
3582   /* Local symbols do not count, but target specific ones might.  */
3583   if (ELF_ST_BIND (sym->st_info) != STB_GLOBAL
3584       && ELF_ST_BIND (sym->st_info) < STB_LOOS)
3585     return false;
3586 
3587   bed = get_elf_backend_data (abfd);
3588   /* Function symbols do not count.  */
3589   if (bed->is_function_type (ELF_ST_TYPE (sym->st_info)))
3590     return false;
3591 
3592   /* If the section is undefined, then so is the symbol.  */
3593   if (sym->st_shndx == SHN_UNDEF)
3594     return false;
3595 
3596   /* If the symbol is defined in the common section, then
3597      it is a common definition and so does not count.  */
3598   if (bed->common_definition (sym))
3599     return false;
3600 
3601   /* If the symbol is in a target specific section then we
3602      must rely upon the backend to tell us what it is.  */
3603   if (sym->st_shndx >= SHN_LORESERVE && sym->st_shndx < SHN_ABS)
3604     /* FIXME - this function is not coded yet:
3605 
3606        return _bfd_is_global_symbol_definition (abfd, sym);
3607 
3608        Instead for now assume that the definition is not global,
3609        Even if this is wrong, at least the linker will behave
3610        in the same way that it used to do.  */
3611     return false;
3612 
3613   return true;
3614 }
3615 
3616 /* Search the symbol table of the archive element of the archive ABFD
3617    whose archive map contains a mention of SYMDEF, and determine if
3618    the symbol is defined in this element.  */
3619 static bool
elf_link_is_defined_archive_symbol(bfd * abfd,carsym * symdef)3620 elf_link_is_defined_archive_symbol (bfd * abfd, carsym * symdef)
3621 {
3622   Elf_Internal_Shdr * hdr;
3623   size_t symcount;
3624   size_t extsymcount;
3625   size_t extsymoff;
3626   Elf_Internal_Sym *isymbuf;
3627   Elf_Internal_Sym *isym;
3628   Elf_Internal_Sym *isymend;
3629   bool result;
3630 
3631   abfd = _bfd_get_elt_at_filepos (abfd, symdef->file_offset, NULL);
3632   if (abfd == NULL)
3633     return false;
3634 
3635   if (! bfd_check_format (abfd, bfd_object))
3636     return false;
3637 
3638   /* Select the appropriate symbol table.  If we don't know if the
3639      object file is an IR object, give linker LTO plugin a chance to
3640      get the correct symbol table.  */
3641   if (abfd->plugin_format == bfd_plugin_yes
3642 #if BFD_SUPPORTS_PLUGINS
3643       || (abfd->plugin_format == bfd_plugin_unknown
3644             && bfd_link_plugin_object_p (abfd))
3645 #endif
3646       )
3647     {
3648       /* Use the IR symbol table if the object has been claimed by
3649            plugin.  */
3650       abfd = abfd->plugin_dummy_bfd;
3651       hdr = &elf_tdata (abfd)->symtab_hdr;
3652     }
3653   else
3654     {
3655       if (elf_use_dt_symtab_p (abfd))
3656           {
3657             bfd_set_error (bfd_error_wrong_format);
3658             return false;
3659           }
3660 
3661       if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
3662           hdr = &elf_tdata (abfd)->symtab_hdr;
3663       else
3664           hdr = &elf_tdata (abfd)->dynsymtab_hdr;
3665     }
3666 
3667   symcount = hdr->sh_size / get_elf_backend_data (abfd)->s->sizeof_sym;
3668 
3669   /* The sh_info field of the symtab header tells us where the
3670      external symbols start.  We don't care about the local symbols.  */
3671   if (elf_bad_symtab (abfd))
3672     {
3673       extsymcount = symcount;
3674       extsymoff = 0;
3675     }
3676   else
3677     {
3678       extsymcount = symcount - hdr->sh_info;
3679       extsymoff = hdr->sh_info;
3680     }
3681 
3682   if (extsymcount == 0)
3683     return false;
3684 
3685   /* Read in the symbol table.  */
3686   isymbuf = bfd_elf_get_elf_syms (abfd, hdr, extsymcount, extsymoff,
3687                                           NULL, NULL, NULL);
3688   if (isymbuf == NULL)
3689     return false;
3690 
3691   /* Scan the symbol table looking for SYMDEF.  */
3692   result = false;
3693   for (isym = isymbuf, isymend = isymbuf + extsymcount; isym < isymend; isym++)
3694     {
3695       const char *name;
3696 
3697       name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link,
3698                                                         isym->st_name);
3699       if (name == NULL)
3700           break;
3701 
3702       if (strcmp (name, symdef->name) == 0)
3703           {
3704             result = is_global_data_symbol_definition (abfd, isym);
3705             break;
3706           }
3707     }
3708 
3709   free (isymbuf);
3710 
3711   return result;
3712 }
3713 
3714 /* Add an entry to the .dynamic table.  */
3715 
3716 bool
_bfd_elf_add_dynamic_entry(struct bfd_link_info * info,bfd_vma tag,bfd_vma val)3717 _bfd_elf_add_dynamic_entry (struct bfd_link_info *info,
3718                                   bfd_vma tag,
3719                                   bfd_vma val)
3720 {
3721   struct elf_link_hash_table *hash_table;
3722   const struct elf_backend_data *bed;
3723   asection *s;
3724   bfd_size_type newsize;
3725   bfd_byte *newcontents;
3726   Elf_Internal_Dyn dyn;
3727 
3728   hash_table = elf_hash_table (info);
3729   if (! is_elf_hash_table (&hash_table->root))
3730     return false;
3731 
3732   if (tag == DT_RELA || tag == DT_REL)
3733     hash_table->dynamic_relocs = true;
3734 
3735   bed = get_elf_backend_data (hash_table->dynobj);
3736   s = hash_table->dynamic;
3737   BFD_ASSERT (s != NULL);
3738 
3739   newsize = s->size + bed->s->sizeof_dyn;
3740   newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
3741   if (newcontents == NULL)
3742     return false;
3743 
3744   dyn.d_tag = tag;
3745   dyn.d_un.d_val = val;
3746   bed->s->swap_dyn_out (hash_table->dynobj, &dyn, newcontents + s->size);
3747 
3748   s->size = newsize;
3749   s->contents = newcontents;
3750 
3751   return true;
3752 }
3753 
3754 /* Strip zero-sized dynamic sections.  */
3755 
3756 bool
_bfd_elf_strip_zero_sized_dynamic_sections(struct bfd_link_info * info)3757 _bfd_elf_strip_zero_sized_dynamic_sections (struct bfd_link_info *info)
3758 {
3759   struct elf_link_hash_table *hash_table;
3760   const struct elf_backend_data *bed;
3761   asection *s, *sdynamic, **pp;
3762   asection *rela_dyn, *rel_dyn;
3763   Elf_Internal_Dyn dyn;
3764   bfd_byte *extdyn, *next;
3765   void (*swap_dyn_in) (bfd *, const void *, Elf_Internal_Dyn *);
3766   bool strip_zero_sized;
3767   bool strip_zero_sized_plt;
3768 
3769   if (bfd_link_relocatable (info))
3770     return true;
3771 
3772   hash_table = elf_hash_table (info);
3773   if (!is_elf_hash_table (&hash_table->root))
3774     return false;
3775 
3776   if (!hash_table->dynobj)
3777     return true;
3778 
3779   sdynamic= hash_table->dynamic;
3780   if (!sdynamic)
3781     return true;
3782 
3783   bed = get_elf_backend_data (hash_table->dynobj);
3784   swap_dyn_in = bed->s->swap_dyn_in;
3785 
3786   strip_zero_sized = false;
3787   strip_zero_sized_plt = false;
3788 
3789   /* Strip zero-sized dynamic sections.  */
3790   rela_dyn = bfd_get_section_by_name (info->output_bfd, ".rela.dyn");
3791   rel_dyn = bfd_get_section_by_name (info->output_bfd, ".rel.dyn");
3792   for (pp = &info->output_bfd->sections; (s = *pp) != NULL;)
3793     if (s->size == 0
3794           && (s == rela_dyn
3795               || s == rel_dyn
3796               || s == hash_table->srelplt->output_section
3797               || s == hash_table->splt->output_section))
3798       {
3799           *pp = s->next;
3800           info->output_bfd->section_count--;
3801           strip_zero_sized = true;
3802           if (s == rela_dyn)
3803             s = rela_dyn;
3804           if (s == rel_dyn)
3805             s = rel_dyn;
3806           else if (s == hash_table->splt->output_section)
3807             {
3808               s = hash_table->splt;
3809               strip_zero_sized_plt = true;
3810             }
3811           else
3812             s = hash_table->srelplt;
3813           s->flags |= SEC_EXCLUDE;
3814           s->output_section = bfd_abs_section_ptr;
3815       }
3816     else
3817       pp = &s->next;
3818 
3819   if (strip_zero_sized_plt && sdynamic->size != 0)
3820     for (extdyn = sdynamic->contents;
3821            extdyn < sdynamic->contents + sdynamic->size;
3822            extdyn = next)
3823       {
3824           next = extdyn + bed->s->sizeof_dyn;
3825           swap_dyn_in (hash_table->dynobj, extdyn, &dyn);
3826           switch (dyn.d_tag)
3827             {
3828             default:
3829               break;
3830             case DT_JMPREL:
3831             case DT_PLTRELSZ:
3832             case DT_PLTREL:
3833               /* Strip DT_PLTRELSZ, DT_JMPREL and DT_PLTREL entries if
3834                  the procedure linkage table (the .plt section) has been
3835                  removed.  */
3836               memmove (extdyn, next,
3837                          sdynamic->size - (next - sdynamic->contents));
3838               next = extdyn;
3839             }
3840       }
3841 
3842   if (strip_zero_sized)
3843     {
3844       /* Regenerate program headers.  */
3845       elf_seg_map (info->output_bfd) = NULL;
3846       return _bfd_elf_map_sections_to_segments (info->output_bfd, info,
3847                                                             NULL);
3848     }
3849 
3850   return true;
3851 }
3852 
3853 /* Add a DT_NEEDED entry for this dynamic object.  Returns -1 on error,
3854    1 if a DT_NEEDED tag already exists, and 0 on success.  */
3855 
3856 int
bfd_elf_add_dt_needed_tag(bfd * abfd,struct bfd_link_info * info)3857 bfd_elf_add_dt_needed_tag (bfd *abfd, struct bfd_link_info *info)
3858 {
3859   struct elf_link_hash_table *hash_table;
3860   size_t strindex;
3861   const char *soname;
3862 
3863   if (!_bfd_elf_link_create_dynstrtab (abfd, info))
3864     return -1;
3865 
3866   hash_table = elf_hash_table (info);
3867   soname = elf_dt_name (abfd);
3868   strindex = _bfd_elf_strtab_add (hash_table->dynstr, soname, false);
3869   if (strindex == (size_t) -1)
3870     return -1;
3871 
3872   if (_bfd_elf_strtab_refcount (hash_table->dynstr, strindex) != 1)
3873     {
3874       asection *sdyn;
3875       const struct elf_backend_data *bed;
3876       bfd_byte *extdyn;
3877 
3878       bed = get_elf_backend_data (hash_table->dynobj);
3879       sdyn = hash_table->dynamic;
3880       if (sdyn != NULL && sdyn->size != 0)
3881           for (extdyn = sdyn->contents;
3882                extdyn < sdyn->contents + sdyn->size;
3883                extdyn += bed->s->sizeof_dyn)
3884             {
3885               Elf_Internal_Dyn dyn;
3886 
3887               bed->s->swap_dyn_in (hash_table->dynobj, extdyn, &dyn);
3888               if (dyn.d_tag == DT_NEEDED
3889                     && dyn.d_un.d_val == strindex)
3890                 {
3891                     _bfd_elf_strtab_delref (hash_table->dynstr, strindex);
3892                     return 1;
3893                 }
3894             }
3895     }
3896 
3897   if (!_bfd_elf_link_create_dynamic_sections (hash_table->dynobj, info))
3898     return -1;
3899 
3900   if (!_bfd_elf_add_dynamic_entry (info, DT_NEEDED, strindex))
3901     return -1;
3902 
3903   return 0;
3904 }
3905 
3906 /* Return true if SONAME is on the needed list between NEEDED and STOP
3907    (or the end of list if STOP is NULL), and needed by a library that
3908    will be loaded.  */
3909 
3910 static bool
on_needed_list(const char * soname,struct bfd_link_needed_list * needed,struct bfd_link_needed_list * stop)3911 on_needed_list (const char *soname,
3912                     struct bfd_link_needed_list *needed,
3913                     struct bfd_link_needed_list *stop)
3914 {
3915   struct bfd_link_needed_list *look;
3916   for (look = needed; look != stop; look = look->next)
3917     if (strcmp (soname, look->name) == 0
3918           && ((elf_dyn_lib_class (look->by) & DYN_AS_NEEDED) == 0
3919               /* If needed by a library that itself is not directly
3920                  needed, recursively check whether that library is
3921                  indirectly needed.  Since we add DT_NEEDED entries to
3922                  the end of the list, library dependencies appear after
3923                  the library.  Therefore search prior to the current
3924                  LOOK, preventing possible infinite recursion.  */
3925               || on_needed_list (elf_dt_name (look->by), needed, look)))
3926       return true;
3927 
3928   return false;
3929 }
3930 
3931 /* Sort symbol by value, section, size, and type.  */
3932 static int
elf_sort_symbol(const void * arg1,const void * arg2)3933 elf_sort_symbol (const void *arg1, const void *arg2)
3934 {
3935   const struct elf_link_hash_entry *h1;
3936   const struct elf_link_hash_entry *h2;
3937   bfd_signed_vma vdiff;
3938   int sdiff;
3939   const char *n1;
3940   const char *n2;
3941 
3942   h1 = *(const struct elf_link_hash_entry **) arg1;
3943   h2 = *(const struct elf_link_hash_entry **) arg2;
3944   vdiff = h1->root.u.def.value - h2->root.u.def.value;
3945   if (vdiff != 0)
3946     return vdiff > 0 ? 1 : -1;
3947 
3948   sdiff = h1->root.u.def.section->id - h2->root.u.def.section->id;
3949   if (sdiff != 0)
3950     return sdiff;
3951 
3952   /* Sort so that sized symbols are selected over zero size symbols.  */
3953   vdiff = h1->size - h2->size;
3954   if (vdiff != 0)
3955     return vdiff > 0 ? 1 : -1;
3956 
3957   /* Sort so that STT_OBJECT is selected over STT_NOTYPE.  */
3958   if (h1->type != h2->type)
3959     return h1->type - h2->type;
3960 
3961   /* If symbols are properly sized and typed, and multiple strong
3962      aliases are not defined in a shared library by the user we
3963      shouldn't get here.  Unfortunately linker script symbols like
3964      __bss_start sometimes match a user symbol defined at the start of
3965      .bss without proper size and type.  We'd like to preference the
3966      user symbol over reserved system symbols.  Sort on leading
3967      underscores.  */
3968   n1 = h1->root.root.string;
3969   n2 = h2->root.root.string;
3970   while (*n1 == *n2)
3971     {
3972       if (*n1 == 0)
3973           break;
3974       ++n1;
3975       ++n2;
3976     }
3977   if (*n1 == '_')
3978     return -1;
3979   if (*n2 == '_')
3980     return 1;
3981 
3982   /* Final sort on name selects user symbols like '_u' over reserved
3983      system symbols like '_Z' and also will avoid qsort instability.  */
3984   return *n1 - *n2;
3985 }
3986 
3987 /* This function is used to adjust offsets into .dynstr for
3988    dynamic symbols.  This is called via elf_link_hash_traverse.  */
3989 
3990 static bool
elf_adjust_dynstr_offsets(struct elf_link_hash_entry * h,void * data)3991 elf_adjust_dynstr_offsets (struct elf_link_hash_entry *h, void *data)
3992 {
3993   struct elf_strtab_hash *dynstr = (struct elf_strtab_hash *) data;
3994 
3995   if (h->dynindx != -1)
3996     h->dynstr_index = _bfd_elf_strtab_offset (dynstr, h->dynstr_index);
3997   return true;
3998 }
3999 
4000 /* Assign string offsets in .dynstr, update all structures referencing
4001    them.  */
4002 
4003 static bool
elf_finalize_dynstr(bfd * output_bfd,struct bfd_link_info * info)4004 elf_finalize_dynstr (bfd *output_bfd, struct bfd_link_info *info)
4005 {
4006   struct elf_link_hash_table *hash_table = elf_hash_table (info);
4007   struct elf_link_local_dynamic_entry *entry;
4008   struct elf_strtab_hash *dynstr = hash_table->dynstr;
4009   bfd *dynobj = hash_table->dynobj;
4010   asection *sdyn;
4011   bfd_size_type size;
4012   const struct elf_backend_data *bed;
4013   bfd_byte *extdyn;
4014 
4015   _bfd_elf_strtab_finalize (dynstr);
4016   size = _bfd_elf_strtab_size (dynstr);
4017 
4018   /* Allow the linker to examine the dynsymtab now it's fully populated.  */
4019 
4020   if (info->callbacks->examine_strtab)
4021     info->callbacks->examine_strtab (dynstr);
4022 
4023   bed = get_elf_backend_data (dynobj);
4024   sdyn = hash_table->dynamic;
4025   BFD_ASSERT (sdyn != NULL);
4026 
4027   /* Update all .dynamic entries referencing .dynstr strings.  */
4028   for (extdyn = sdyn->contents;
4029        extdyn < PTR_ADD (sdyn->contents, sdyn->size);
4030        extdyn += bed->s->sizeof_dyn)
4031     {
4032       Elf_Internal_Dyn dyn;
4033 
4034       bed->s->swap_dyn_in (dynobj, extdyn, &dyn);
4035       switch (dyn.d_tag)
4036           {
4037           case DT_STRSZ:
4038             dyn.d_un.d_val = size;
4039             break;
4040           case DT_NEEDED:
4041           case DT_SONAME:
4042           case DT_RPATH:
4043           case DT_RUNPATH:
4044           case DT_FILTER:
4045           case DT_AUXILIARY:
4046           case DT_AUDIT:
4047           case DT_DEPAUDIT:
4048             dyn.d_un.d_val = _bfd_elf_strtab_offset (dynstr, dyn.d_un.d_val);
4049             break;
4050           default:
4051             continue;
4052           }
4053       bed->s->swap_dyn_out (dynobj, &dyn, extdyn);
4054     }
4055 
4056   /* Now update local dynamic symbols.  */
4057   for (entry = hash_table->dynlocal; entry ; entry = entry->next)
4058     entry->isym.st_name = _bfd_elf_strtab_offset (dynstr,
4059                                                               entry->isym.st_name);
4060 
4061   /* And the rest of dynamic symbols.  */
4062   elf_link_hash_traverse (hash_table, elf_adjust_dynstr_offsets, dynstr);
4063 
4064   /* Adjust version definitions.  */
4065   if (elf_tdata (output_bfd)->cverdefs)
4066     {
4067       asection *s;
4068       bfd_byte *p;
4069       size_t i;
4070       Elf_Internal_Verdef def;
4071       Elf_Internal_Verdaux defaux;
4072 
4073       s = bfd_get_linker_section (dynobj, ".gnu.version_d");
4074       p = s->contents;
4075       do
4076           {
4077             _bfd_elf_swap_verdef_in (output_bfd, (Elf_External_Verdef *) p,
4078                                            &def);
4079             p += sizeof (Elf_External_Verdef);
4080             if (def.vd_aux != sizeof (Elf_External_Verdef))
4081               continue;
4082             for (i = 0; i < def.vd_cnt; ++i)
4083               {
4084                 _bfd_elf_swap_verdaux_in (output_bfd,
4085                                                   (Elf_External_Verdaux *) p, &defaux);
4086                 defaux.vda_name = _bfd_elf_strtab_offset (dynstr,
4087                                                                       defaux.vda_name);
4088                 _bfd_elf_swap_verdaux_out (output_bfd,
4089                                                    &defaux, (Elf_External_Verdaux *) p);
4090                 p += sizeof (Elf_External_Verdaux);
4091               }
4092           }
4093       while (def.vd_next);
4094     }
4095 
4096   /* Adjust version references.  */
4097   if (elf_tdata (output_bfd)->verref)
4098     {
4099       asection *s;
4100       bfd_byte *p;
4101       size_t i;
4102       Elf_Internal_Verneed need;
4103       Elf_Internal_Vernaux needaux;
4104 
4105       s = bfd_get_linker_section (dynobj, ".gnu.version_r");
4106       p = s->contents;
4107       do
4108           {
4109             _bfd_elf_swap_verneed_in (output_bfd, (Elf_External_Verneed *) p,
4110                                             &need);
4111             need.vn_file = _bfd_elf_strtab_offset (dynstr, need.vn_file);
4112             _bfd_elf_swap_verneed_out (output_bfd, &need,
4113                                              (Elf_External_Verneed *) p);
4114             p += sizeof (Elf_External_Verneed);
4115             for (i = 0; i < need.vn_cnt; ++i)
4116               {
4117                 _bfd_elf_swap_vernaux_in (output_bfd,
4118                                                   (Elf_External_Vernaux *) p, &needaux);
4119                 needaux.vna_name = _bfd_elf_strtab_offset (dynstr,
4120                                                                        needaux.vna_name);
4121                 _bfd_elf_swap_vernaux_out (output_bfd,
4122                                                    &needaux,
4123                                                    (Elf_External_Vernaux *) p);
4124                 p += sizeof (Elf_External_Vernaux);
4125               }
4126           }
4127       while (need.vn_next);
4128     }
4129 
4130   return true;
4131 }
4132 
4133 /* Return TRUE iff relocations for INPUT are compatible with OUTPUT.
4134    The default is to only match when the INPUT and OUTPUT are exactly
4135    the same target.  */
4136 
4137 bool
_bfd_elf_default_relocs_compatible(const bfd_target * input,const bfd_target * output)4138 _bfd_elf_default_relocs_compatible (const bfd_target *input,
4139                                             const bfd_target *output)
4140 {
4141   return input == output;
4142 }
4143 
4144 /* Return TRUE iff relocations for INPUT are compatible with OUTPUT.
4145    This version is used when different targets for the same architecture
4146    are virtually identical.  */
4147 
4148 bool
_bfd_elf_relocs_compatible(const bfd_target * input,const bfd_target * output)4149 _bfd_elf_relocs_compatible (const bfd_target *input,
4150                                   const bfd_target *output)
4151 {
4152   const struct elf_backend_data *obed, *ibed;
4153 
4154   if (input == output)
4155     return true;
4156 
4157   ibed = xvec_get_elf_backend_data (input);
4158   obed = xvec_get_elf_backend_data (output);
4159 
4160   if (ibed->arch != obed->arch)
4161     return false;
4162 
4163   /* If both backends are using this function, deem them compatible.  */
4164   return ibed->relocs_compatible == obed->relocs_compatible;
4165 }
4166 
4167 /* Make a special call to the linker "notice" function to tell it that
4168    we are about to handle an as-needed lib, or have finished
4169    processing the lib.  */
4170 
4171 bool
_bfd_elf_notice_as_needed(bfd * ibfd,struct bfd_link_info * info,enum notice_asneeded_action act)4172 _bfd_elf_notice_as_needed (bfd *ibfd,
4173                                  struct bfd_link_info *info,
4174                                  enum notice_asneeded_action act)
4175 {
4176   return (*info->callbacks->notice) (info, NULL, NULL, ibfd, NULL, act, 0);
4177 }
4178 
4179 /* Call ACTION on each relocation in an ELF object file.  */
4180 
4181 bool
_bfd_elf_link_iterate_on_relocs(bfd * abfd,struct bfd_link_info * info,bool (* action)(bfd *,struct bfd_link_info *,asection *,const Elf_Internal_Rela *))4182 _bfd_elf_link_iterate_on_relocs
4183   (bfd *abfd, struct bfd_link_info *info,
4184    bool (*action) (bfd *, struct bfd_link_info *, asection *,
4185                        const Elf_Internal_Rela *))
4186 {
4187   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
4188   struct elf_link_hash_table *htab = elf_hash_table (info);
4189 
4190   /* If this object is the same format as the output object, and it is
4191      not a shared library, then let the backend look through the
4192      relocs.
4193 
4194      This is required to build global offset table entries and to
4195      arrange for dynamic relocs.  It is not required for the
4196      particular common case of linking non PIC code, even when linking
4197      against shared libraries, but unfortunately there is no way of
4198      knowing whether an object file has been compiled PIC or not.
4199      Looking through the relocs is not particularly time consuming.
4200      The problem is that we must either (1) keep the relocs in memory,
4201      which causes the linker to require additional runtime memory or
4202      (2) read the relocs twice from the input file, which wastes time.
4203      This would be a good case for using mmap.
4204 
4205      I have no idea how to handle linking PIC code into a file of a
4206      different format.  It probably can't be done.  */
4207   if ((abfd->flags & DYNAMIC) == 0
4208       && is_elf_hash_table (&htab->root)
4209       && elf_object_id (abfd) == elf_hash_table_id (htab)
4210       && (*bed->relocs_compatible) (abfd->xvec, info->output_bfd->xvec))
4211     {
4212       asection *o;
4213 
4214       for (o = abfd->sections; o != NULL; o = o->next)
4215           {
4216             Elf_Internal_Rela *internal_relocs;
4217             bool ok;
4218 
4219             /* Don't check relocations in excluded sections.  Don't do
4220                anything special with non-loaded, non-alloced sections.
4221                In particular, any relocs in such sections should not
4222                affect GOT and PLT reference counting (ie.  we don't
4223                allow them to create GOT or PLT entries), there's no
4224                possibility or desire to optimize TLS relocs, and
4225                there's not much point in propagating relocs to shared
4226                libs that the dynamic linker won't relocate.  */
4227             if ((o->flags & SEC_ALLOC) == 0
4228                 || (o->flags & SEC_RELOC) == 0
4229                 || (o->flags & SEC_EXCLUDE) != 0
4230                 || o->reloc_count == 0
4231                 || ((info->strip == strip_all || info->strip == strip_debugger)
4232                       && (o->flags & SEC_DEBUGGING) != 0)
4233                 || bfd_is_abs_section (o->output_section))
4234               continue;
4235 
4236             internal_relocs = _bfd_elf_link_info_read_relocs
4237               (abfd, info, o, NULL, NULL,
4238                _bfd_elf_link_keep_memory (info));
4239             if (internal_relocs == NULL)
4240               return false;
4241 
4242             ok = action (abfd, info, o, internal_relocs);
4243 
4244             if (elf_section_data (o)->relocs != internal_relocs)
4245               free (internal_relocs);
4246 
4247             if (! ok)
4248               return false;
4249           }
4250     }
4251 
4252   return true;
4253 }
4254 
4255 /* Check relocations in an ELF object file.  This is called after
4256    all input files have been opened.  */
4257 
4258 bool
_bfd_elf_link_check_relocs(bfd * abfd,struct bfd_link_info * info)4259 _bfd_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
4260 {
4261   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
4262   if (bed->check_relocs != NULL)
4263     return _bfd_elf_link_iterate_on_relocs (abfd, info,
4264                                                       bed->check_relocs);
4265   return true;
4266 }
4267 
4268 /* An entry in the first definition hash table.  */
4269 
4270 struct elf_link_first_hash_entry
4271 {
4272   struct bfd_hash_entry root;
4273   /* The object of the first definition.  */
4274   bfd *abfd;
4275 };
4276 
4277 /* The function to create a new entry in the first definition hash
4278    table.  */
4279 
4280 static struct bfd_hash_entry *
elf_link_first_hash_newfunc(struct bfd_hash_entry * entry,struct bfd_hash_table * table,const char * string)4281 elf_link_first_hash_newfunc (struct bfd_hash_entry *entry,
4282                                    struct bfd_hash_table *table,
4283                                    const char *string)
4284 {
4285   struct elf_link_first_hash_entry *ret =
4286     (struct elf_link_first_hash_entry *) entry;
4287 
4288   /* Allocate the structure if it has not already been allocated by a
4289      subclass.  */
4290   if (ret == NULL)
4291     ret = (struct elf_link_first_hash_entry *)
4292           bfd_hash_allocate (table,
4293                                  sizeof (struct elf_link_first_hash_entry));
4294   if (ret == NULL)
4295     return NULL;
4296 
4297   /* Call the allocation method of the superclass.  */
4298   ret = ((struct elf_link_first_hash_entry *)
4299            bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table,
4300                                  string));
4301   if (ret != NULL)
4302     ret->abfd = NULL;
4303 
4304   return (struct bfd_hash_entry *) ret;
4305 }
4306 
4307 /* Add the symbol NAME from ABFD to first hash.  */
4308 
4309 static void
elf_link_add_to_first_hash(bfd * abfd,struct bfd_link_info * info,const char * name,bool copy)4310 elf_link_add_to_first_hash (bfd *abfd, struct bfd_link_info *info,
4311                                   const char *name, bool copy)
4312 {
4313   struct elf_link_hash_table *htab = elf_hash_table (info);
4314   /* Skip if there is no first hash.  */
4315   if (htab->first_hash == NULL)
4316     return;
4317 
4318   struct elf_link_first_hash_entry *e
4319     = ((struct elf_link_first_hash_entry *)
4320        bfd_hash_lookup (htab->first_hash, name, true, copy));
4321   if (e == NULL)
4322     info->callbacks->einfo
4323       (_("%F%P: %pB: failed to add %s to first hash\n"), abfd, name);
4324 
4325   if (e->abfd == NULL)
4326     /* Store ABFD in abfd.  */
4327     e->abfd = abfd;
4328 }
4329 
4330 /* Add symbols from an ELF object file to the linker hash table.  */
4331 
4332 static bool
elf_link_add_object_symbols(bfd * abfd,struct bfd_link_info * info)4333 elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
4334 {
4335   Elf_Internal_Ehdr *ehdr;
4336   Elf_Internal_Shdr *hdr;
4337   size_t symcount;
4338   size_t extsymcount;
4339   size_t extsymoff;
4340   struct elf_link_hash_entry **sym_hash;
4341   bool dynamic;
4342   Elf_External_Versym *extversym = NULL;
4343   Elf_External_Versym *extversym_end = NULL;
4344   Elf_External_Versym *ever;
4345   struct elf_link_hash_entry *weaks;
4346   struct elf_link_hash_entry **nondeflt_vers = NULL;
4347   size_t nondeflt_vers_cnt = 0;
4348   Elf_Internal_Sym *isymbuf = NULL;
4349   Elf_Internal_Sym *isym;
4350   Elf_Internal_Sym *isymend;
4351   const struct elf_backend_data *bed;
4352   bool add_needed;
4353   struct elf_link_hash_table *htab;
4354   void *alloc_mark = NULL;
4355   struct bfd_hash_entry **old_table = NULL;
4356   unsigned int old_size = 0;
4357   unsigned int old_count = 0;
4358   void *old_tab = NULL;
4359   void *old_ent;
4360   struct bfd_link_hash_entry *old_undefs = NULL;
4361   struct bfd_link_hash_entry *old_undefs_tail = NULL;
4362   void *old_strtab = NULL;
4363   size_t tabsize = 0;
4364   asection *s;
4365   bool just_syms;
4366 
4367   htab = elf_hash_table (info);
4368   bed = get_elf_backend_data (abfd);
4369 
4370   if (elf_use_dt_symtab_p (abfd))
4371     {
4372       bfd_set_error (bfd_error_wrong_format);
4373       return false;
4374     }
4375 
4376   if ((abfd->flags & DYNAMIC) == 0)
4377     {
4378       dynamic = false;
4379       if ((abfd->flags & BFD_PLUGIN) != 0
4380             && is_elf_hash_table (&htab->root)
4381             && htab->first_hash == NULL)
4382           {
4383             /* Initialize first_hash for an IR input.  */
4384             htab->first_hash = (struct bfd_hash_table *)
4385               bfd_malloc (sizeof (struct bfd_hash_table));
4386             if (htab->first_hash == NULL
4387                 || !bfd_hash_table_init
4388                        (htab->first_hash, elf_link_first_hash_newfunc,
4389                         sizeof (struct elf_link_first_hash_entry)))
4390               info->callbacks->einfo
4391                 (_("%F%P: first_hash failed to create: %E\n"));
4392           }
4393     }
4394   else
4395     {
4396       dynamic = true;
4397 
4398       /* You can't use -r against a dynamic object.  Also, there's no
4399            hope of using a dynamic object which does not exactly match
4400            the format of the output file.  */
4401       if (bfd_link_relocatable (info)
4402             || !is_elf_hash_table (&htab->root)
4403             || info->output_bfd->xvec != abfd->xvec)
4404           {
4405             if (bfd_link_relocatable (info))
4406               bfd_set_error (bfd_error_invalid_operation);
4407             else
4408               bfd_set_error (bfd_error_wrong_format);
4409             goto error_return;
4410           }
4411     }
4412 
4413   ehdr = elf_elfheader (abfd);
4414   if (info->warn_alternate_em
4415       && bed->elf_machine_code != ehdr->e_machine
4416       && ((bed->elf_machine_alt1 != 0
4417              && ehdr->e_machine == bed->elf_machine_alt1)
4418             || (bed->elf_machine_alt2 != 0
4419                 && ehdr->e_machine == bed->elf_machine_alt2)))
4420     _bfd_error_handler
4421       /* xgettext:c-format */
4422       (_("alternate ELF machine code found (%d) in %pB, expecting %d"),
4423        ehdr->e_machine, abfd, bed->elf_machine_code);
4424 
4425   /* As a GNU extension, any input sections which are named
4426      .gnu.warning.SYMBOL are treated as warning symbols for the given
4427      symbol.  This differs from .gnu.warning sections, which generate
4428      warnings when they are included in an output file.  */
4429   /* PR 12761: Also generate this warning when building shared libraries.  */
4430   for (s = abfd->sections; s != NULL; s = s->next)
4431     {
4432       const char *name;
4433 
4434       name = bfd_section_name (s);
4435       if (startswith (name, ".gnu.warning."))
4436           {
4437             char *msg;
4438             bfd_size_type sz;
4439 
4440             name += sizeof ".gnu.warning." - 1;
4441 
4442             /* If this is a shared object, then look up the symbol
4443                in the hash table.  If it is there, and it is already
4444                been defined, then we will not be using the entry
4445                from this shared object, so we don't need to warn.
4446                FIXME: If we see the definition in a regular object
4447                later on, we will warn, but we shouldn't.  The only
4448                fix is to keep track of what warnings we are supposed
4449                to emit, and then handle them all at the end of the
4450                link.  */
4451             if (dynamic)
4452               {
4453                 struct elf_link_hash_entry *h;
4454 
4455                 h = elf_link_hash_lookup (htab, name, false, false, true);
4456 
4457                 /* FIXME: What about bfd_link_hash_common?  */
4458                 if (h != NULL
4459                       && (h->root.type == bfd_link_hash_defined
4460                           || h->root.type == bfd_link_hash_defweak))
4461                     continue;
4462               }
4463 
4464             sz = s->size;
4465             msg = (char *) bfd_alloc (abfd, sz + 1);
4466             if (msg == NULL)
4467               goto error_return;
4468 
4469             if (! bfd_get_section_contents (abfd, s, msg, 0, sz))
4470               goto error_return;
4471 
4472             msg[sz] = '\0';
4473 
4474             if (! (_bfd_generic_link_add_one_symbol
4475                      (info, abfd, name, BSF_WARNING, s, 0, msg,
4476                       false, bed->collect, NULL)))
4477               goto error_return;
4478 
4479             if (bfd_link_executable (info))
4480               {
4481                 /* Clobber the section size so that the warning does
4482                      not get copied into the output file.  */
4483                 s->size = 0;
4484 
4485                 /* Also set SEC_EXCLUDE, so that symbols defined in
4486                      the warning section don't get copied to the output.  */
4487                 s->flags |= SEC_EXCLUDE;
4488               }
4489           }
4490     }
4491 
4492   just_syms = ((s = abfd->sections) != NULL
4493                  && s->sec_info_type == SEC_INFO_TYPE_JUST_SYMS);
4494 
4495   add_needed = true;
4496   if (! dynamic)
4497     {
4498       /* If we are creating a shared library, create all the dynamic
4499            sections immediately.  We need to attach them to something,
4500            so we attach them to this BFD, provided it is the right
4501            format and is not from ld --just-symbols.  Always create the
4502            dynamic sections for -E/--dynamic-list.  FIXME: If there
4503            are no input BFD's of the same format as the output, we can't
4504            make a shared library.  */
4505       if (!just_syms
4506             && (bfd_link_pic (info)
4507                 || (!bfd_link_relocatable (info)
4508                       && info->nointerp
4509                       && (info->export_dynamic || info->dynamic)))
4510             && is_elf_hash_table (&htab->root)
4511             && info->output_bfd->xvec == abfd->xvec
4512             && !htab->dynamic_sections_created)
4513           {
4514             if (! _bfd_elf_link_create_dynamic_sections (abfd, info))
4515               goto error_return;
4516           }
4517     }
4518   else if (!is_elf_hash_table (&htab->root))
4519     goto error_return;
4520   else
4521     {
4522       const char *soname = NULL;
4523       char *audit = NULL;
4524       struct bfd_link_needed_list *rpath = NULL, *runpath = NULL;
4525       const Elf_Internal_Phdr *phdr;
4526       struct elf_link_loaded_list *loaded_lib;
4527 
4528       /* ld --just-symbols and dynamic objects don't mix very well.
4529            ld shouldn't allow it.  */
4530       if (just_syms)
4531           abort ();
4532 
4533       /* If this dynamic lib was specified on the command line with
4534            --as-needed in effect, then we don't want to add a DT_NEEDED
4535            tag unless the lib is actually used.  Similary for libs brought
4536            in by another lib's DT_NEEDED.  When --no-add-needed is used
4537            on a dynamic lib, we don't want to add a DT_NEEDED entry for
4538            any dynamic library in DT_NEEDED tags in the dynamic lib at
4539            all.  */
4540       add_needed = (elf_dyn_lib_class (abfd)
4541                         & (DYN_AS_NEEDED | DYN_DT_NEEDED
4542                            | DYN_NO_NEEDED)) == 0;
4543 
4544       s = bfd_get_section_by_name (abfd, ".dynamic");
4545       if (s != NULL && s->size != 0 && (s->flags & SEC_HAS_CONTENTS) != 0)
4546           {
4547             bfd_byte *dynbuf;
4548             bfd_byte *extdyn;
4549             unsigned int elfsec;
4550             unsigned long shlink;
4551 
4552             if (!_bfd_elf_mmap_section_contents (abfd, s, &dynbuf))
4553               {
4554               error_free_dyn:
4555                 _bfd_elf_munmap_section_contents (s, dynbuf);
4556                 goto error_return;
4557               }
4558 
4559             elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
4560             if (elfsec == SHN_BAD)
4561               goto error_free_dyn;
4562             shlink = elf_elfsections (abfd)[elfsec]->sh_link;
4563 
4564             for (extdyn = dynbuf;
4565                  (size_t) (dynbuf + s->size - extdyn) >= bed->s->sizeof_dyn;
4566                  extdyn += bed->s->sizeof_dyn)
4567               {
4568                 Elf_Internal_Dyn dyn;
4569 
4570                 bed->s->swap_dyn_in (abfd, extdyn, &dyn);
4571                 if (dyn.d_tag == DT_SONAME)
4572                     {
4573                       unsigned int tagv = dyn.d_un.d_val;
4574                       soname = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
4575                       if (soname == NULL)
4576                         goto error_free_dyn;
4577                     }
4578                 if (dyn.d_tag == DT_NEEDED)
4579                     {
4580                       struct bfd_link_needed_list *n, **pn;
4581                       char *fnm, *anm;
4582                       unsigned int tagv = dyn.d_un.d_val;
4583                       size_t amt = sizeof (struct bfd_link_needed_list);
4584 
4585                       n = (struct bfd_link_needed_list *) bfd_alloc (abfd, amt);
4586                       fnm = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
4587                       if (n == NULL || fnm == NULL)
4588                         goto error_free_dyn;
4589                       amt = strlen (fnm) + 1;
4590                       anm = (char *) bfd_alloc (abfd, amt);
4591                       if (anm == NULL)
4592                         goto error_free_dyn;
4593                       memcpy (anm, fnm, amt);
4594                       n->name = anm;
4595                       n->by = abfd;
4596                       n->next = NULL;
4597                       for (pn = &htab->needed; *pn != NULL; pn = &(*pn)->next)
4598                         ;
4599                       *pn = n;
4600                     }
4601                 if (dyn.d_tag == DT_RUNPATH)
4602                     {
4603                       struct bfd_link_needed_list *n, **pn;
4604                       char *fnm, *anm;
4605                       unsigned int tagv = dyn.d_un.d_val;
4606                       size_t amt = sizeof (struct bfd_link_needed_list);
4607 
4608                       n = (struct bfd_link_needed_list *) bfd_alloc (abfd, amt);
4609                       fnm = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
4610                       if (n == NULL || fnm == NULL)
4611                         goto error_free_dyn;
4612                       amt = strlen (fnm) + 1;
4613                       anm = (char *) bfd_alloc (abfd, amt);
4614                       if (anm == NULL)
4615                         goto error_free_dyn;
4616                       memcpy (anm, fnm, amt);
4617                       n->name = anm;
4618                       n->by = abfd;
4619                       n->next = NULL;
4620                       for (pn = & runpath;
4621                            *pn != NULL;
4622                            pn = &(*pn)->next)
4623                         ;
4624                       *pn = n;
4625                     }
4626                 /* Ignore DT_RPATH if we have seen DT_RUNPATH.  */
4627                 if (!runpath && dyn.d_tag == DT_RPATH)
4628                     {
4629                       struct bfd_link_needed_list *n, **pn;
4630                       char *fnm, *anm;
4631                       unsigned int tagv = dyn.d_un.d_val;
4632                       size_t amt = sizeof (struct bfd_link_needed_list);
4633 
4634                       n = (struct bfd_link_needed_list *) bfd_alloc (abfd, amt);
4635                       fnm = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
4636                       if (n == NULL || fnm == NULL)
4637                         goto error_free_dyn;
4638                       amt = strlen (fnm) + 1;
4639                       anm = (char *) bfd_alloc (abfd, amt);
4640                       if (anm == NULL)
4641                         goto error_free_dyn;
4642                       memcpy (anm, fnm, amt);
4643                       n->name = anm;
4644                       n->by = abfd;
4645                       n->next = NULL;
4646                       for (pn = & rpath;
4647                            *pn != NULL;
4648                            pn = &(*pn)->next)
4649                         ;
4650                       *pn = n;
4651                     }
4652                 if (dyn.d_tag == DT_AUDIT)
4653                     {
4654                       unsigned int tagv = dyn.d_un.d_val;
4655                       audit = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
4656                     }
4657                 if (dyn.d_tag == DT_FLAGS_1)
4658                     elf_tdata (abfd)->is_pie = (dyn.d_un.d_val & DF_1_PIE) != 0;
4659               }
4660 
4661             _bfd_elf_munmap_section_contents (s, dynbuf);
4662           }
4663 
4664       /* DT_RUNPATH overrides DT_RPATH.  Do _NOT_ bfd_release, as that
4665            frees all more recently bfd_alloc'd blocks as well.  */
4666       if (runpath)
4667           rpath = runpath;
4668 
4669       if (rpath)
4670           {
4671             struct bfd_link_needed_list **pn;
4672             for (pn = &htab->runpath; *pn != NULL; pn = &(*pn)->next)
4673               ;
4674             *pn = rpath;
4675           }
4676 
4677       /* If we have a PT_GNU_RELRO program header, mark as read-only
4678            all sections contained fully therein.  This makes relro
4679            shared library sections appear as they will at run-time.  */
4680       phdr = elf_tdata (abfd)->phdr + elf_elfheader (abfd)->e_phnum;
4681       while (phdr-- > elf_tdata (abfd)->phdr)
4682           if (phdr->p_type == PT_GNU_RELRO)
4683             {
4684               for (s = abfd->sections; s != NULL; s = s->next)
4685                 {
4686                     unsigned int opb = bfd_octets_per_byte (abfd, s);
4687 
4688                     if ((s->flags & SEC_ALLOC) != 0
4689                         && s->vma * opb >= phdr->p_vaddr
4690                         && s->vma * opb + s->size <= phdr->p_vaddr + phdr->p_memsz)
4691                       s->flags |= SEC_READONLY;
4692                 }
4693               break;
4694             }
4695 
4696       /* We do not want to include any of the sections in a dynamic
4697            object in the output file.  We hack by simply clobbering the
4698            list of sections in the BFD.  This could be handled more
4699            cleanly by, say, a new section flag; the existing
4700            SEC_NEVER_LOAD flag is not the one we want, because that one
4701            still implies that the section takes up space in the output
4702            file.  */
4703       bfd_section_list_clear (abfd);
4704 
4705       /* Find the name to use in a DT_NEEDED entry that refers to this
4706            object.  If the object has a DT_SONAME entry, we use it.
4707            Otherwise, if the generic linker stuck something in
4708            elf_dt_name, we use that.  Otherwise, we just use the file
4709            name.  */
4710       if (soname == NULL || *soname == '\0')
4711           {
4712             soname = elf_dt_name (abfd);
4713             if (soname == NULL || *soname == '\0')
4714               soname = bfd_get_filename (abfd);
4715           }
4716 
4717       /* Save the SONAME because sometimes the linker emulation code
4718            will need to know it.  */
4719       elf_dt_name (abfd) = soname;
4720 
4721       /* If we have already included this dynamic object in the
4722            link, just ignore it.  There is no reason to include a
4723            particular dynamic object more than once.  */
4724       for (loaded_lib = htab->dyn_loaded;
4725              loaded_lib != NULL;
4726              loaded_lib = loaded_lib->next)
4727           {
4728             if (strcmp (elf_dt_name (loaded_lib->abfd), soname) == 0)
4729               return true;
4730           }
4731 
4732       /* Create dynamic sections for backends that require that be done
4733            before setup_gnu_properties.  */
4734       if (add_needed
4735             && !_bfd_elf_link_create_dynamic_sections (abfd, info))
4736           return false;
4737 
4738       /* Save the DT_AUDIT entry for the linker emulation code. */
4739       elf_dt_audit (abfd) = audit;
4740     }
4741 
4742   /* If this is a dynamic object, we always link against the .dynsym
4743      symbol table, not the .symtab symbol table.  The dynamic linker
4744      will only see the .dynsym symbol table, so there is no reason to
4745      look at .symtab for a dynamic object.  */
4746 
4747   if (! dynamic || elf_dynsymtab (abfd) == 0)
4748     hdr = &elf_tdata (abfd)->symtab_hdr;
4749   else
4750     hdr = &elf_tdata (abfd)->dynsymtab_hdr;
4751 
4752   symcount = hdr->sh_size / bed->s->sizeof_sym;
4753 
4754   /* The sh_info field of the symtab header tells us where the
4755      external symbols start.  We don't care about the local symbols at
4756      this point.  */
4757   if (elf_bad_symtab (abfd))
4758     {
4759       extsymcount = symcount;
4760       extsymoff = 0;
4761     }
4762   else
4763     {
4764       extsymcount = symcount - hdr->sh_info;
4765       extsymoff = hdr->sh_info;
4766     }
4767 
4768   sym_hash = elf_sym_hashes (abfd);
4769   if (extsymcount != 0)
4770     {
4771       isymbuf = bfd_elf_get_elf_syms (abfd, hdr, extsymcount, extsymoff,
4772                                               NULL, NULL, NULL);
4773       if (isymbuf == NULL)
4774           goto error_return;
4775 
4776       if (sym_hash == NULL)
4777           {
4778             /* We store a pointer to the hash table entry for each
4779                external symbol.  */
4780             size_t amt = extsymcount * sizeof (struct elf_link_hash_entry *);
4781             sym_hash = (struct elf_link_hash_entry **) bfd_zalloc (abfd, amt);
4782             if (sym_hash == NULL)
4783               goto error_free_sym;
4784             elf_sym_hashes (abfd) = sym_hash;
4785           }
4786     }
4787 
4788   if (dynamic)
4789     {
4790       /* Read in any version definitions.  */
4791       if (!_bfd_elf_slurp_version_tables (abfd,
4792                                                     info->default_imported_symver))
4793           goto error_free_sym;
4794 
4795       /* Read in the symbol versions, but don't bother to convert them
4796            to internal format.  */
4797       if (elf_dynversym (abfd) != 0)
4798           {
4799             Elf_Internal_Shdr *versymhdr = &elf_tdata (abfd)->dynversym_hdr;
4800             bfd_size_type amt = versymhdr->sh_size;
4801 
4802             if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0)
4803               goto error_free_sym;
4804             extversym = (Elf_External_Versym *)
4805               _bfd_malloc_and_read (abfd, amt, amt);
4806             if (extversym == NULL)
4807               goto error_free_sym;
4808             extversym_end = extversym + amt / sizeof (*extversym);
4809           }
4810     }
4811 
4812   /* If we are loading an as-needed shared lib, save the symbol table
4813      state before we start adding symbols.  If the lib turns out
4814      to be unneeded, restore the state.  */
4815   if ((elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0)
4816     {
4817       unsigned int i;
4818       size_t entsize;
4819 
4820       for (entsize = 0, i = 0; i < htab->root.table.size; i++)
4821           {
4822             struct bfd_hash_entry *p;
4823             struct elf_link_hash_entry *h;
4824 
4825             for (p = htab->root.table.table[i]; p != NULL; p = p->next)
4826               {
4827                 h = (struct elf_link_hash_entry *) p;
4828                 entsize += htab->root.table.entsize;
4829                 if (h->root.type == bfd_link_hash_warning)
4830                     {
4831                       entsize += htab->root.table.entsize;
4832                       h = (struct elf_link_hash_entry *) h->root.u.i.link;
4833                     }
4834                 if (h->root.type == bfd_link_hash_common)
4835                     entsize += sizeof (*h->root.u.c.p);
4836               }
4837           }
4838 
4839       tabsize = htab->root.table.size * sizeof (struct bfd_hash_entry *);
4840       old_tab = bfd_malloc (tabsize + entsize);
4841       if (old_tab == NULL)
4842           goto error_free_vers;
4843 
4844       /* Remember the current objalloc pointer, so that all mem for
4845            symbols added can later be reclaimed.  */
4846       alloc_mark = bfd_hash_allocate (&htab->root.table, 1);
4847       if (alloc_mark == NULL)
4848           goto error_free_vers;
4849 
4850       /* Make a special call to the linker "notice" function to
4851            tell it that we are about to handle an as-needed lib.  */
4852       if (!(*bed->notice_as_needed) (abfd, info, notice_as_needed))
4853           goto error_free_vers;
4854 
4855       /* Clone the symbol table.  Remember some pointers into the
4856            symbol table, and dynamic symbol count.  */
4857       old_ent = (char *) old_tab + tabsize;
4858       memcpy (old_tab, htab->root.table.table, tabsize);
4859       old_undefs = htab->root.undefs;
4860       old_undefs_tail = htab->root.undefs_tail;
4861       old_table = htab->root.table.table;
4862       old_size = htab->root.table.size;
4863       old_count = htab->root.table.count;
4864       old_strtab = NULL;
4865       if (htab->dynstr != NULL)
4866           {
4867             old_strtab = _bfd_elf_strtab_save (htab->dynstr);
4868             if (old_strtab == NULL)
4869               goto error_free_vers;
4870           }
4871 
4872       for (i = 0; i < htab->root.table.size; i++)
4873           {
4874             struct bfd_hash_entry *p;
4875             struct elf_link_hash_entry *h;
4876 
4877             for (p = htab->root.table.table[i]; p != NULL; p = p->next)
4878               {
4879                 h = (struct elf_link_hash_entry *) p;
4880                 memcpy (old_ent, h, htab->root.table.entsize);
4881                 old_ent = (char *) old_ent + htab->root.table.entsize;
4882                 if (h->root.type == bfd_link_hash_warning)
4883                     {
4884                       h = (struct elf_link_hash_entry *) h->root.u.i.link;
4885                       memcpy (old_ent, h, htab->root.table.entsize);
4886                       old_ent = (char *) old_ent + htab->root.table.entsize;
4887                     }
4888                 if (h->root.type == bfd_link_hash_common)
4889                     {
4890                       memcpy (old_ent, h->root.u.c.p, sizeof (*h->root.u.c.p));
4891                       old_ent = (char *) old_ent + sizeof (*h->root.u.c.p);
4892                     }
4893               }
4894           }
4895     }
4896 
4897   weaks = NULL;
4898   if (extversym == NULL)
4899     ever = NULL;
4900   else if (extversym + extsymoff < extversym_end)
4901     ever = extversym + extsymoff;
4902   else
4903     {
4904       /* xgettext:c-format */
4905       _bfd_error_handler (_("%pB: invalid version offset %lx (max %lx)"),
4906                                 abfd, (long) extsymoff,
4907                                 (long) (extversym_end - extversym) / sizeof (* extversym));
4908       bfd_set_error (bfd_error_bad_value);
4909       goto error_free_vers;
4910     }
4911 
4912   if (!bfd_link_relocatable (info)
4913       && bfd_get_lto_type (abfd) == lto_slim_ir_object)
4914     {
4915       _bfd_error_handler
4916           (_("%pB: plugin needed to handle lto object"), abfd);
4917     }
4918 
4919   for (isym = isymbuf, isymend = PTR_ADD (isymbuf, extsymcount);
4920        isym < isymend;
4921        isym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
4922     {
4923       int bind;
4924       bfd_vma value;
4925       asection *sec, *new_sec;
4926       flagword flags;
4927       const char *name;
4928       bool must_copy_name = false;
4929       struct elf_link_hash_entry *h;
4930       struct elf_link_hash_entry *hi;
4931       bool definition;
4932       bool size_change_ok;
4933       bool type_change_ok;
4934       bool new_weak;
4935       bool old_weak;
4936       bfd *override;
4937       bool common;
4938       bool discarded;
4939       unsigned int old_alignment;
4940       unsigned int shindex;
4941       bfd *old_bfd;
4942       bool matched;
4943 
4944       override = NULL;
4945 
4946       flags = BSF_NO_FLAGS;
4947       sec = NULL;
4948       value = isym->st_value;
4949       common = bed->common_definition (isym);
4950       if (common && info->inhibit_common_definition)
4951           {
4952             /* Treat common symbol as undefined for --no-define-common.  */
4953             isym->st_shndx = SHN_UNDEF;
4954             common = false;
4955           }
4956       discarded = false;
4957 
4958       bind = ELF_ST_BIND (isym->st_info);
4959       switch (bind)
4960           {
4961           case STB_LOCAL:
4962             /* This should be impossible, since ELF requires that all
4963                global symbols follow all local symbols, and that sh_info
4964                point to the first global symbol.  Unfortunately, Irix 5
4965                screws this up.  */
4966             if (elf_bad_symtab (abfd))
4967               continue;
4968 
4969             /* If we aren't prepared to handle locals within the globals
4970                then we'll likely segfault on a NULL symbol hash if the
4971                symbol is ever referenced in relocations.  */
4972             shindex = elf_elfheader (abfd)->e_shstrndx;
4973             name = bfd_elf_string_from_elf_section (abfd, shindex, hdr->sh_name);
4974             _bfd_error_handler (_("%pB: %s local symbol at index %lu"
4975                                         " (>= sh_info of %lu)"),
4976                                     abfd, name, (long) (isym - isymbuf + extsymoff),
4977                                     (long) extsymoff);
4978 
4979             /* Dynamic object relocations are not processed by ld, so
4980                ld won't run into the problem mentioned above.  */
4981             if (dynamic)
4982               continue;
4983             bfd_set_error (bfd_error_bad_value);
4984             goto error_free_vers;
4985 
4986           case STB_GLOBAL:
4987             if (isym->st_shndx != SHN_UNDEF && !common)
4988               flags = BSF_GLOBAL;
4989             break;
4990 
4991           case STB_WEAK:
4992             flags = BSF_WEAK;
4993             break;
4994 
4995           case STB_GNU_UNIQUE:
4996             flags = BSF_GNU_UNIQUE;
4997             break;
4998 
4999           default:
5000             /* Leave it up to the processor backend.  */
5001             break;
5002           }
5003 
5004       if (isym->st_shndx == SHN_UNDEF)
5005           sec = bfd_und_section_ptr;
5006       else if (isym->st_shndx == SHN_ABS)
5007           sec = bfd_abs_section_ptr;
5008       else if (isym->st_shndx == SHN_COMMON)
5009           {
5010             sec = bfd_com_section_ptr;
5011             /* What ELF calls the size we call the value.  What ELF
5012                calls the value we call the alignment.  */
5013             value = isym->st_size;
5014           }
5015       else
5016           {
5017             sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
5018             if (sec == NULL)
5019               sec = bfd_abs_section_ptr;
5020             else if (discarded_section (sec))
5021               {
5022                 /* Symbols from discarded section are undefined.  We keep
5023                      its visibility.  */
5024                 sec = bfd_und_section_ptr;
5025                 discarded = true;
5026                 isym->st_shndx = SHN_UNDEF;
5027               }
5028             else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
5029               value -= sec->vma;
5030           }
5031 
5032       name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link,
5033                                                         isym->st_name);
5034       if (name == NULL)
5035           goto error_free_vers;
5036 
5037       if (isym->st_shndx == SHN_COMMON
5038             && (abfd->flags & BFD_PLUGIN) != 0)
5039           {
5040             asection *xc = bfd_get_section_by_name (abfd, "COMMON");
5041 
5042             if (xc == NULL)
5043               {
5044                 flagword sflags = (SEC_ALLOC | SEC_IS_COMMON | SEC_KEEP
5045                                          | SEC_EXCLUDE);
5046                 xc = bfd_make_section_with_flags (abfd, "COMMON", sflags);
5047                 if (xc == NULL)
5048                     goto error_free_vers;
5049               }
5050             sec = xc;
5051           }
5052       else if (isym->st_shndx == SHN_COMMON
5053                  && ELF_ST_TYPE (isym->st_info) == STT_TLS
5054                  && !bfd_link_relocatable (info))
5055           {
5056             asection *tcomm = bfd_get_section_by_name (abfd, ".tcommon");
5057 
5058             if (tcomm == NULL)
5059               {
5060                 flagword sflags = (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_IS_COMMON
5061                                          | SEC_LINKER_CREATED);
5062                 tcomm = bfd_make_section_with_flags (abfd, ".tcommon", sflags);
5063                 if (tcomm == NULL)
5064                     goto error_free_vers;
5065               }
5066             sec = tcomm;
5067           }
5068       else if (bed->elf_add_symbol_hook)
5069           {
5070             if (! (*bed->elf_add_symbol_hook) (abfd, info, isym, &name, &flags,
5071                                                        &sec, &value))
5072               goto error_free_vers;
5073 
5074             /* The hook function sets the name to NULL if this symbol
5075                should be skipped for some reason.  */
5076             if (name == NULL)
5077               continue;
5078           }
5079 
5080       /* Sanity check that all possibilities were handled.  */
5081       if (sec == NULL)
5082           abort ();
5083 
5084       /* Silently discard TLS symbols from --just-syms.  There's
5085            no way to combine a static TLS block with a new TLS block
5086            for this executable.  */
5087       if (ELF_ST_TYPE (isym->st_info) == STT_TLS
5088             && sec->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
5089           continue;
5090 
5091       if (bfd_is_und_section (sec)
5092             || bfd_is_com_section (sec))
5093           definition = false;
5094       else
5095           definition = true;
5096 
5097       size_change_ok = false;
5098       type_change_ok = bed->type_change_ok;
5099       old_weak = false;
5100       matched = false;
5101       old_alignment = 0;
5102       old_bfd = NULL;
5103       new_sec = sec;
5104 
5105       if (is_elf_hash_table (&htab->root))
5106           {
5107             Elf_Internal_Versym iver;
5108             unsigned int vernum = 0;
5109             bool skip;
5110 
5111             if (ever == NULL)
5112               {
5113                 if (info->default_imported_symver)
5114                     /* Use the default symbol version created earlier.  */
5115                     iver.vs_vers = elf_tdata (abfd)->cverdefs;
5116                 else
5117                     iver.vs_vers = 0;
5118               }
5119             else if (ever >= extversym_end)
5120               {
5121                 /* xgettext:c-format */
5122                 _bfd_error_handler (_("%pB: not enough version information"),
5123                                           abfd);
5124                 bfd_set_error (bfd_error_bad_value);
5125                 goto error_free_vers;
5126               }
5127             else
5128               _bfd_elf_swap_versym_in (abfd, ever, &iver);
5129 
5130             vernum = iver.vs_vers & VERSYM_VERSION;
5131 
5132             /* If this is a hidden symbol, or if it is not version
5133                1, we append the version name to the symbol name.
5134                However, we do not modify a non-hidden absolute symbol
5135                if it is not a function, because it might be the version
5136                symbol itself.  FIXME: What if it isn't?  */
5137             if ((iver.vs_vers & VERSYM_HIDDEN) != 0
5138                 || (vernum > 1
5139                       && (!bfd_is_abs_section (sec)
5140                           || bed->is_function_type (ELF_ST_TYPE (isym->st_info)))))
5141               {
5142                 const char *verstr;
5143                 size_t namelen, verlen, newlen;
5144                 char *newname, *p;
5145 
5146                 if (isym->st_shndx != SHN_UNDEF)
5147                     {
5148                       if (vernum > elf_tdata (abfd)->cverdefs)
5149                         verstr = NULL;
5150                       else if (vernum > 1)
5151                         verstr =
5152                           elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
5153                       else
5154                         verstr = "";
5155 
5156                       if (verstr == NULL)
5157                         {
5158                           _bfd_error_handler
5159                               /* xgettext:c-format */
5160                               (_("%pB: %s: invalid version %u (max %d)"),
5161                                abfd, name, vernum,
5162                                elf_tdata (abfd)->cverdefs);
5163                           bfd_set_error (bfd_error_bad_value);
5164                           goto error_free_vers;
5165                         }
5166                     }
5167                 else
5168                     {
5169                       /* We cannot simply test for the number of
5170                          entries in the VERNEED section since the
5171                          numbers for the needed versions do not start
5172                          at 0.  */
5173                       Elf_Internal_Verneed *t;
5174 
5175                       verstr = NULL;
5176                       for (t = elf_tdata (abfd)->verref;
5177                            t != NULL;
5178                            t = t->vn_nextref)
5179                         {
5180                           Elf_Internal_Vernaux *a;
5181 
5182                           for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
5183                               {
5184                                 if (a->vna_other == vernum)
5185                                   {
5186                                     verstr = a->vna_nodename;
5187                                     break;
5188                                   }
5189                               }
5190                           if (a != NULL)
5191                               break;
5192                         }
5193                       if (verstr == NULL)
5194                         {
5195                           _bfd_error_handler
5196                               /* xgettext:c-format */
5197                               (_("%pB: %s: invalid needed version %d"),
5198                                abfd, name, vernum);
5199                           bfd_set_error (bfd_error_bad_value);
5200                           goto error_free_vers;
5201                         }
5202                     }
5203 
5204                 namelen = strlen (name);
5205                 verlen = strlen (verstr);
5206                 newlen = namelen + verlen + 2;
5207                 if ((iver.vs_vers & VERSYM_HIDDEN) == 0
5208                       && isym->st_shndx != SHN_UNDEF)
5209                     ++newlen;
5210 
5211                 newname = (char *) bfd_hash_allocate (&htab->root.table, newlen);
5212                 if (newname == NULL)
5213                     goto error_free_vers;
5214                 memcpy (newname, name, namelen);
5215                 p = newname + namelen;
5216                 *p++ = ELF_VER_CHR;
5217                 /* If this is a defined non-hidden version symbol,
5218                      we add another @ to the name.  This indicates the
5219                      default version of the symbol.  */
5220                 if ((iver.vs_vers & VERSYM_HIDDEN) == 0
5221                       && isym->st_shndx != SHN_UNDEF)
5222                     *p++ = ELF_VER_CHR;
5223                 memcpy (p, verstr, verlen + 1);
5224 
5225                 name = newname;
5226                 /* Since bfd_hash_alloc is used for "name", the string
5227                      must be copied if added to first_hash.  The string
5228                      memory can be freed when an --as-needed library is
5229                      not needed.  */
5230                 must_copy_name = true;
5231               }
5232 
5233             /* If this symbol has default visibility and the user has
5234                requested we not re-export it, then mark it as hidden.  */
5235             if (!bfd_is_und_section (sec)
5236                 && !dynamic
5237                 && abfd->no_export
5238                 && ELF_ST_VISIBILITY (isym->st_other) != STV_INTERNAL)
5239               isym->st_other = (STV_HIDDEN
5240                                     | (isym->st_other & ~ELF_ST_VISIBILITY (-1)));
5241 
5242             if (!_bfd_elf_merge_symbol (abfd, info, name, isym, &sec, &value,
5243                                               sym_hash, &old_bfd, &old_weak,
5244                                               &old_alignment, &skip, &override,
5245                                               &type_change_ok, &size_change_ok,
5246                                               &matched))
5247               goto error_free_vers;
5248 
5249             if (skip)
5250               continue;
5251 
5252             h = *sym_hash;
5253             while (h->root.type == bfd_link_hash_indirect
5254                      || h->root.type == bfd_link_hash_warning)
5255               h = (struct elf_link_hash_entry *) h->root.u.i.link;
5256 
5257             /* Override a definition only if the new symbol matches the
5258                existing one.  */
5259             if (override && matched)
5260               {
5261                 definition = false;
5262                 if (htab->first_hash != NULL
5263                       && (elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0
5264                       && h->root.non_ir_ref_regular)
5265                     {
5266                       /* When reloading --as-needed shared objects for new
5267                          symbols added from IR inputs, if this shared object
5268                          has the first definition, use it.  */
5269                       struct elf_link_first_hash_entry *e
5270                         = ((struct elf_link_first_hash_entry *)
5271                            bfd_hash_lookup (htab->first_hash, name, false,
5272                                                   false));
5273                       if (e != NULL && e->abfd == abfd)
5274                         definition = true;
5275                     }
5276               }
5277 
5278             if (h->versioned != unversioned
5279                 && elf_tdata (abfd)->verdef != NULL
5280                 && vernum > 1
5281                 && definition)
5282               h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
5283           }
5284 
5285       if (! (_bfd_generic_link_add_one_symbol
5286                (info, override ? override : abfd, name, flags, sec, value,
5287                 NULL, false, bed->collect,
5288                 (struct bfd_link_hash_entry **) sym_hash)))
5289           goto error_free_vers;
5290 
5291       h = *sym_hash;
5292       /* We need to make sure that indirect symbol dynamic flags are
5293            updated.  */
5294       hi = h;
5295       while (h->root.type == bfd_link_hash_indirect
5296                || h->root.type == bfd_link_hash_warning)
5297           h = (struct elf_link_hash_entry *) h->root.u.i.link;
5298 
5299       *sym_hash = h;
5300 
5301       /* Setting the index to -3 tells elf_link_output_extsym that
5302            this symbol is defined in a discarded section.  */
5303       if (discarded && is_elf_hash_table (&htab->root))
5304           h->indx = -3;
5305 
5306       new_weak = (flags & BSF_WEAK) != 0;
5307       if (dynamic
5308             && definition
5309             && new_weak
5310             && !bed->is_function_type (ELF_ST_TYPE (isym->st_info))
5311             && is_elf_hash_table (&htab->root)
5312             && h->u.alias == NULL)
5313           {
5314             /* Keep a list of all weak defined non function symbols from
5315                a dynamic object, using the alias field.  Later in this
5316                function we will set the alias field to the correct
5317                value.  We only put non-function symbols from dynamic
5318                objects on this list, because that happens to be the only
5319                time we need to know the normal symbol corresponding to a
5320                weak symbol, and the information is time consuming to
5321                figure out.  If the alias field is not already NULL,
5322                then this symbol was already defined by some previous
5323                dynamic object, and we will be using that previous
5324                definition anyhow.  */
5325 
5326             h->u.alias = weaks;
5327             weaks = h;
5328           }
5329 
5330       /* Set the alignment of a common symbol.  */
5331       if ((common || bfd_is_com_section (sec))
5332             && h->root.type == bfd_link_hash_common)
5333           {
5334             unsigned int align;
5335 
5336             if (common)
5337               align = bfd_log2 (isym->st_value);
5338             else
5339               {
5340                 /* The new symbol is a common symbol in a shared object.
5341                      We need to get the alignment from the section.  */
5342                 align = new_sec->alignment_power;
5343               }
5344             if (align > old_alignment)
5345               h->root.u.c.p->alignment_power = align;
5346             else
5347               h->root.u.c.p->alignment_power = old_alignment;
5348           }
5349 
5350       if (is_elf_hash_table (&htab->root))
5351           {
5352             /* Set a flag in the hash table entry indicating the type of
5353                reference or definition we just found.  A dynamic symbol
5354                is one which is referenced or defined by both a regular
5355                object and a shared object.  */
5356             bool dynsym = false;
5357 
5358             /* Plugin symbols aren't normal.  Don't set def/ref flags.  */
5359             if ((abfd->flags & BFD_PLUGIN) != 0)
5360               {
5361                 /* Except for this flag to track nonweak references.  */
5362                 if (!definition
5363                       && bind != STB_WEAK)
5364                     h->ref_ir_nonweak = 1;
5365               }
5366             else if (!dynamic)
5367               {
5368                 if (! definition)
5369                     {
5370                       h->ref_regular = 1;
5371                       if (bind != STB_WEAK)
5372                         h->ref_regular_nonweak = 1;
5373                     }
5374                 else
5375                     {
5376                       h->def_regular = 1;
5377                       if (h->def_dynamic)
5378                         {
5379                           h->def_dynamic = 0;
5380                           h->ref_dynamic = 1;
5381                         }
5382                     }
5383               }
5384             else
5385               {
5386                 if (! definition)
5387                     {
5388                       h->ref_dynamic = 1;
5389                       hi->ref_dynamic = 1;
5390                     }
5391                 else
5392                     {
5393                       h->def_dynamic = 1;
5394                       hi->def_dynamic = 1;
5395                     }
5396               }
5397 
5398             /* If an indirect symbol has been forced local, don't
5399                make the real symbol dynamic.  */
5400             if (h != hi && hi->forced_local)
5401               ;
5402             else if (!dynamic)
5403               {
5404                 if (bfd_link_dll (info)
5405                       || h->def_dynamic
5406                       || h->ref_dynamic)
5407                     dynsym = true;
5408               }
5409             else
5410               {
5411                 if (h->def_regular
5412                       || h->ref_regular
5413                       || (h->is_weakalias
5414                           && weakdef (h)->dynindx != -1))
5415                     dynsym = true;
5416               }
5417 
5418             /* Check to see if we need to add an indirect symbol for
5419                the default name.  */
5420             if ((definition
5421                  || (!override && h->root.type == bfd_link_hash_common))
5422                 && !(hi != h
5423                        && hi->versioned == versioned_hidden))
5424               if (!_bfd_elf_add_default_symbol (abfd, info, h, name, isym,
5425                                                         sec, value, &old_bfd, &dynsym))
5426                 goto error_free_vers;
5427 
5428             /* Check the alignment when a common symbol is involved. This
5429                can change when a common symbol is overridden by a normal
5430                definition or a common symbol is ignored due to the old
5431                normal definition. We need to make sure the maximum
5432                alignment is maintained.  */
5433             if ((old_alignment || common)
5434                 && h->root.type != bfd_link_hash_common)
5435               {
5436                 unsigned int common_align;
5437                 unsigned int normal_align;
5438                 unsigned int symbol_align;
5439                 bfd *normal_bfd;
5440                 bfd *common_bfd;
5441 
5442                 BFD_ASSERT (h->root.type == bfd_link_hash_defined
5443                                 || h->root.type == bfd_link_hash_defweak);
5444 
5445                 symbol_align = ffs (h->root.u.def.value) - 1;
5446                 if (h->root.u.def.section->owner != NULL
5447                       && (h->root.u.def.section->owner->flags
5448                            & (DYNAMIC | BFD_PLUGIN)) == 0)
5449                     {
5450                       normal_align = h->root.u.def.section->alignment_power;
5451                       if (normal_align > symbol_align)
5452                         normal_align = symbol_align;
5453                     }
5454                 else
5455                     normal_align = symbol_align;
5456 
5457                 if (old_alignment)
5458                     {
5459                       common_align = old_alignment;
5460                       common_bfd = old_bfd;
5461                       normal_bfd = abfd;
5462                     }
5463                 else
5464                     {
5465                       common_align = bfd_log2 (isym->st_value);
5466                       common_bfd = abfd;
5467                       normal_bfd = old_bfd;
5468                     }
5469 
5470                 if (normal_align < common_align)
5471                     {
5472                       /* PR binutils/2735 */
5473                       if (normal_bfd == NULL)
5474                         _bfd_error_handler
5475                           /* xgettext:c-format */
5476                           (_("warning: alignment %u of common symbol `%s' in %pB is"
5477                                " greater than the alignment (%u) of its section %pA"),
5478                            1 << common_align, name, common_bfd,
5479                            1 << normal_align, h->root.u.def.section);
5480                       else
5481                         _bfd_error_handler
5482                           /* xgettext:c-format */
5483                           (_("warning: alignment %u of normal symbol `%s' in %pB"
5484                                " is smaller than %u used by the common definition in %pB"),
5485                            1 << normal_align, name, normal_bfd,
5486                            1 << common_align, common_bfd);
5487 
5488                       /* PR 30499: make sure that users understand that this warning is serious.  */
5489                       _bfd_error_handler
5490                         (_("warning: NOTE: alignment discrepancies can cause real problems.  Investigation is advised."));
5491                     }
5492               }
5493 
5494             /* Remember the symbol size if it isn't undefined.  */
5495             if (isym->st_size != 0
5496                 && isym->st_shndx != SHN_UNDEF
5497                 && (definition || h->size == 0))
5498               {
5499                 if (h->size != 0
5500                       && h->size != isym->st_size
5501                       && ! size_change_ok)
5502                     {
5503                       _bfd_error_handler
5504                         /* xgettext:c-format */
5505                         (_("warning: size of symbol `%s' changed"
5506                            " from %" PRIu64 " in %pB to %" PRIu64 " in %pB"),
5507                          name, (uint64_t) h->size, old_bfd,
5508                          (uint64_t) isym->st_size, abfd);
5509 
5510                       /* PR 30499: make sure that users understand that this warning is serious.  */
5511                       _bfd_error_handler
5512                         (_("warning: NOTE: size discrepancies can cause real problems.  Investigation is advised."));
5513                     }
5514 
5515                 h->size = isym->st_size;
5516               }
5517 
5518             /* If this is a common symbol, then we always want H->SIZE
5519                to be the size of the common symbol.  The code just above
5520                won't fix the size if a common symbol becomes larger.  We
5521                don't warn about a size change here, because that is
5522                covered by --warn-common.  Allow changes between different
5523                function types.  */
5524             if (h->root.type == bfd_link_hash_common)
5525               h->size = h->root.u.c.size;
5526 
5527             if (ELF_ST_TYPE (isym->st_info) != STT_NOTYPE
5528                 && ((definition && !new_weak)
5529                       || (old_weak && h->root.type == bfd_link_hash_common)
5530                       || h->type == STT_NOTYPE))
5531               {
5532                 unsigned int type = ELF_ST_TYPE (isym->st_info);
5533 
5534                 /* Turn an IFUNC symbol from a DSO into a normal FUNC
5535                      symbol.  */
5536                 if (type == STT_GNU_IFUNC
5537                       && (abfd->flags & DYNAMIC) != 0)
5538                     type = STT_FUNC;
5539 
5540                 if (h->type != type)
5541                     {
5542                       if (h->type != STT_NOTYPE && ! type_change_ok)
5543                         /* xgettext:c-format */
5544                         _bfd_error_handler
5545                           (_("warning: type of symbol `%s' changed"
5546                                " from %d to %d in %pB"),
5547                            name, h->type, type, abfd);
5548 
5549                       h->type = type;
5550                     }
5551               }
5552 
5553             /* Merge st_other field.  */
5554             elf_merge_st_other (abfd, h, isym->st_other, sec,
5555                                     definition, dynamic);
5556 
5557             /* We don't want to make debug symbol dynamic.  */
5558             if (definition
5559                 && (sec->flags & SEC_DEBUGGING)
5560                 && !bfd_link_relocatable (info))
5561               dynsym = false;
5562 
5563             /* Nor should we make plugin symbols dynamic.  */
5564             if ((abfd->flags & BFD_PLUGIN) != 0)
5565               dynsym = false;
5566 
5567             if (definition)
5568               {
5569                 h->target_internal = isym->st_target_internal;
5570                 h->unique_global = (flags & BSF_GNU_UNIQUE) != 0;
5571               }
5572 
5573             /* Don't add indirect symbols for .symver x, x@FOO aliases
5574                in IR.  Since all data or text symbols in IR have the
5575                same type, value and section, we can't tell if a symbol
5576                is an alias of another symbol by their types, values and
5577                sections.  */
5578             if (definition
5579                 && !dynamic
5580                 && (abfd->flags & BFD_PLUGIN) == 0)
5581               {
5582                 char *p = strchr (name, ELF_VER_CHR);
5583                 if (p != NULL && p[1] != ELF_VER_CHR)
5584                     {
5585                       /* Queue non-default versions so that .symver x, x@FOO
5586                          aliases can be checked.  */
5587                       if (!nondeflt_vers)
5588                         {
5589                           size_t amt = ((isymend - isym + 1)
5590                                             * sizeof (struct elf_link_hash_entry *));
5591                           nondeflt_vers
5592                               = (struct elf_link_hash_entry **) bfd_malloc (amt);
5593                           if (!nondeflt_vers)
5594                               goto error_free_vers;
5595                         }
5596                       nondeflt_vers[nondeflt_vers_cnt++] = h;
5597                     }
5598               }
5599 
5600             if (dynsym && h->dynindx == -1)
5601               {
5602                 if (! bfd_elf_link_record_dynamic_symbol (info, h))
5603                     goto error_free_vers;
5604                 if (h->is_weakalias
5605                       && weakdef (h)->dynindx == -1)
5606                     {
5607                       if (!bfd_elf_link_record_dynamic_symbol (info, weakdef (h)))
5608                         goto error_free_vers;
5609                     }
5610               }
5611             else if (h->dynindx != -1)
5612               /* If the symbol already has a dynamic index, but
5613                  visibility says it should not be visible, turn it into
5614                  a local symbol.  */
5615               switch (ELF_ST_VISIBILITY (h->other))
5616                 {
5617                 case STV_INTERNAL:
5618                 case STV_HIDDEN:
5619                     (*bed->elf_backend_hide_symbol) (info, h, true);
5620                     dynsym = false;
5621                     break;
5622                 }
5623 
5624             if (!add_needed
5625                 && matched
5626                 && definition
5627                 && h->root.type != bfd_link_hash_indirect)
5628               {
5629                 if ((dynsym
5630                        && h->ref_regular_nonweak)
5631                       || (old_bfd != NULL
5632                           && (old_bfd->flags & BFD_PLUGIN) != 0
5633                           && h->ref_ir_nonweak
5634                           && !info->lto_all_symbols_read)
5635                       || (h->ref_dynamic_nonweak
5636                           && (elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0
5637                           && !on_needed_list (elf_dt_name (abfd),
5638                                                     htab->needed, NULL)))
5639                     {
5640                       const char *soname = elf_dt_name (abfd);
5641 
5642                       info->callbacks->minfo ("%!", soname, old_bfd,
5643                                                     h->root.root.string);
5644 
5645                       /* A symbol from a library loaded via DT_NEEDED of some
5646                          other library is referenced by a regular object.
5647                          Add a DT_NEEDED entry for it.  Issue an error if
5648                          --no-add-needed is used and the reference was not
5649                          a weak one.  */
5650                       if (old_bfd != NULL
5651                           && (elf_dyn_lib_class (abfd) & DYN_NO_NEEDED) != 0)
5652                         {
5653                           _bfd_error_handler
5654                               /* xgettext:c-format */
5655                               (_("%pB: undefined reference to symbol '%s'"),
5656                                old_bfd, name);
5657                           bfd_set_error (bfd_error_missing_dso);
5658                           goto error_free_vers;
5659                         }
5660 
5661                       elf_dyn_lib_class (abfd) = (enum dynamic_lib_link_class)
5662                         (elf_dyn_lib_class (abfd) & ~DYN_AS_NEEDED);
5663 
5664                       /* Create dynamic sections for backends that require
5665                          that be done before setup_gnu_properties.  */
5666                       if (!_bfd_elf_link_create_dynamic_sections (abfd, info))
5667                         return false;
5668                       add_needed = true;
5669                     }
5670                 else if (dynamic
5671                            && h->root.u.def.section->owner == abfd)
5672                     /* Add this symbol to first hash if this shared
5673                        object has the first definition.  */
5674                     elf_link_add_to_first_hash (abfd, info, name, must_copy_name);
5675               }
5676           }
5677     }
5678 
5679   if (info->lto_plugin_active
5680       && !bfd_link_relocatable (info)
5681       && (abfd->flags & BFD_PLUGIN) == 0
5682       && !just_syms
5683       && extsymcount)
5684     {
5685       int r_sym_shift;
5686 
5687       if (bed->s->arch_size == 32)
5688           r_sym_shift = 8;
5689       else
5690           r_sym_shift = 32;
5691 
5692       /* If linker plugin is enabled, set non_ir_ref_regular on symbols
5693            referenced in regular objects so that linker plugin will get
5694            the correct symbol resolution.  */
5695 
5696       sym_hash = elf_sym_hashes (abfd);
5697       for (s = abfd->sections; s != NULL; s = s->next)
5698           {
5699             Elf_Internal_Rela *internal_relocs;
5700             Elf_Internal_Rela *rel, *relend;
5701 
5702             /* Don't check relocations in excluded sections.  */
5703             if ((s->flags & SEC_RELOC) == 0
5704                 || s->reloc_count == 0
5705                 || (s->flags & SEC_EXCLUDE) != 0
5706                 || ((info->strip == strip_all
5707                        || info->strip == strip_debugger)
5708                       && (s->flags & SEC_DEBUGGING) != 0))
5709               continue;
5710 
5711             internal_relocs = _bfd_elf_link_info_read_relocs
5712               (abfd, info, s, NULL, NULL,
5713                _bfd_elf_link_keep_memory (info));
5714             if (internal_relocs == NULL)
5715               goto error_free_vers;
5716 
5717             rel = internal_relocs;
5718             relend = rel + s->reloc_count;
5719             for ( ; rel < relend; rel++)
5720               {
5721                 unsigned long r_symndx = rel->r_info >> r_sym_shift;
5722                 struct elf_link_hash_entry *h;
5723 
5724                 /* Skip local symbols.  */
5725                 if (r_symndx < extsymoff)
5726                     continue;
5727 
5728                 h = sym_hash[r_symndx - extsymoff];
5729                 if (h != NULL)
5730                     h->root.non_ir_ref_regular = 1;
5731               }
5732 
5733             if (elf_section_data (s)->relocs != internal_relocs)
5734               free (internal_relocs);
5735           }
5736     }
5737 
5738   free (extversym);
5739   extversym = NULL;
5740   free (isymbuf);
5741   isymbuf = NULL;
5742 
5743   if ((elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0)
5744     {
5745       unsigned int i;
5746 
5747       /* Restore the symbol table.  */
5748       old_ent = (char *) old_tab + tabsize;
5749       memset (elf_sym_hashes (abfd), 0,
5750                 extsymcount * sizeof (struct elf_link_hash_entry *));
5751       htab->root.table.table = old_table;
5752       htab->root.table.size = old_size;
5753       htab->root.table.count = old_count;
5754       memcpy (htab->root.table.table, old_tab, tabsize);
5755       htab->root.undefs = old_undefs;
5756       htab->root.undefs_tail = old_undefs_tail;
5757       if (htab->dynstr != NULL)
5758           _bfd_elf_strtab_restore (htab->dynstr, old_strtab);
5759       free (old_strtab);
5760       old_strtab = NULL;
5761       for (i = 0; i < htab->root.table.size; i++)
5762           {
5763             struct bfd_hash_entry *p;
5764             struct elf_link_hash_entry *h;
5765             unsigned int non_ir_ref_dynamic;
5766 
5767             for (p = htab->root.table.table[i]; p != NULL; p = p->next)
5768               {
5769                 /* Preserve non_ir_ref_dynamic so that this symbol
5770                      will be exported when the dynamic lib becomes needed
5771                      in the second pass.  */
5772                 h = (struct elf_link_hash_entry *) p;
5773                 if (h->root.type == bfd_link_hash_warning)
5774                     h = (struct elf_link_hash_entry *) h->root.u.i.link;
5775                 non_ir_ref_dynamic = h->root.non_ir_ref_dynamic;
5776 
5777                 h = (struct elf_link_hash_entry *) p;
5778                 memcpy (h, old_ent, htab->root.table.entsize);
5779                 old_ent = (char *) old_ent + htab->root.table.entsize;
5780                 if (h->root.type == bfd_link_hash_warning)
5781                     {
5782                       h = (struct elf_link_hash_entry *) h->root.u.i.link;
5783                       memcpy (h, old_ent, htab->root.table.entsize);
5784                       old_ent = (char *) old_ent + htab->root.table.entsize;
5785                     }
5786                 if (h->root.type == bfd_link_hash_common)
5787                     {
5788                       memcpy (h->root.u.c.p, old_ent, sizeof (*h->root.u.c.p));
5789                       old_ent = (char *) old_ent + sizeof (*h->root.u.c.p);
5790                     }
5791                 h->root.non_ir_ref_dynamic = non_ir_ref_dynamic;
5792               }
5793           }
5794 
5795       /* Make a special call to the linker "notice" function to
5796            tell it that symbols added for crefs may need to be removed.  */
5797       if (!(*bed->notice_as_needed) (abfd, info, notice_not_needed))
5798           goto error_free_vers;
5799 
5800       free (old_tab);
5801       objalloc_free_block ((struct objalloc *) htab->root.table.memory,
5802                                  alloc_mark);
5803       free (nondeflt_vers);
5804       return true;
5805     }
5806 
5807   if (old_tab != NULL)
5808     {
5809       if (!(*bed->notice_as_needed) (abfd, info, notice_needed))
5810           goto error_free_vers;
5811       free (old_tab);
5812       old_tab = NULL;
5813     }
5814 
5815   /* Now that all the symbols from this input file are created, if
5816      not performing a relocatable link, handle .symver foo, foo@BAR
5817      such that any relocs against foo become foo@BAR.  */
5818   if (!bfd_link_relocatable (info) && nondeflt_vers != NULL)
5819     {
5820       size_t cnt, symidx;
5821 
5822       for (cnt = 0; cnt < nondeflt_vers_cnt; ++cnt)
5823           {
5824             struct elf_link_hash_entry *h = nondeflt_vers[cnt], *hi;
5825             char *shortname, *p;
5826             size_t amt;
5827 
5828             p = strchr (h->root.root.string, ELF_VER_CHR);
5829             if (p == NULL
5830                 || (h->root.type != bfd_link_hash_defined
5831                       && h->root.type != bfd_link_hash_defweak))
5832               continue;
5833 
5834             amt = p - h->root.root.string;
5835             shortname = (char *) bfd_malloc (amt + 1);
5836             if (!shortname)
5837               goto error_free_vers;
5838             memcpy (shortname, h->root.root.string, amt);
5839             shortname[amt] = '\0';
5840 
5841             hi = (struct elf_link_hash_entry *)
5842                  bfd_link_hash_lookup (&htab->root, shortname,
5843                                              false, false, false);
5844             if (hi != NULL
5845                 && hi->root.type == h->root.type
5846                 && hi->root.u.def.value == h->root.u.def.value
5847                 && hi->root.u.def.section == h->root.u.def.section)
5848               {
5849                 (*bed->elf_backend_hide_symbol) (info, hi, true);
5850                 hi->root.type = bfd_link_hash_indirect;
5851                 hi->root.u.i.link = (struct bfd_link_hash_entry *) h;
5852                 (*bed->elf_backend_copy_indirect_symbol) (info, h, hi);
5853                 sym_hash = elf_sym_hashes (abfd);
5854                 if (sym_hash)
5855                     for (symidx = 0; symidx < extsymcount; ++symidx)
5856                       if (sym_hash[symidx] == hi)
5857                         {
5858                           sym_hash[symidx] = h;
5859                           break;
5860                         }
5861               }
5862             free (shortname);
5863           }
5864       free (nondeflt_vers);
5865       nondeflt_vers = NULL;
5866     }
5867 
5868   /* Now set the alias field correctly for all the weak defined
5869      symbols we found.  The only way to do this is to search all the
5870      symbols.  Since we only need the information for non functions in
5871      dynamic objects, that's the only time we actually put anything on
5872      the list WEAKS.  We need this information so that if a regular
5873      object refers to a symbol defined weakly in a dynamic object, the
5874      real symbol in the dynamic object is also put in the dynamic
5875      symbols; we also must arrange for both symbols to point to the
5876      same memory location.  We could handle the general case of symbol
5877      aliasing, but a general symbol alias can only be generated in
5878      assembler code, handling it correctly would be very time
5879      consuming, and other ELF linkers don't handle general aliasing
5880      either.  */
5881   if (weaks != NULL)
5882     {
5883       struct elf_link_hash_entry **hpp;
5884       struct elf_link_hash_entry **hppend;
5885       struct elf_link_hash_entry **sorted_sym_hash;
5886       struct elf_link_hash_entry *h;
5887       size_t sym_count, amt;
5888 
5889       /* Since we have to search the whole symbol list for each weak
5890            defined symbol, search time for N weak defined symbols will be
5891            O(N^2). Binary search will cut it down to O(NlogN).  */
5892       amt = extsymcount * sizeof (*sorted_sym_hash);
5893       sorted_sym_hash = bfd_malloc (amt);
5894       if (sorted_sym_hash == NULL)
5895           goto error_return;
5896       sym_hash = sorted_sym_hash;
5897       hpp = elf_sym_hashes (abfd);
5898       hppend = hpp + extsymcount;
5899       sym_count = 0;
5900       for (; hpp < hppend; hpp++)
5901           {
5902             h = *hpp;
5903             if (h != NULL
5904                 && h->root.type == bfd_link_hash_defined
5905                 && !bed->is_function_type (h->type))
5906               {
5907                 *sym_hash = h;
5908                 sym_hash++;
5909                 sym_count++;
5910               }
5911           }
5912 
5913       qsort (sorted_sym_hash, sym_count, sizeof (*sorted_sym_hash),
5914                elf_sort_symbol);
5915 
5916       while (weaks != NULL)
5917           {
5918             struct elf_link_hash_entry *hlook;
5919             asection *slook;
5920             bfd_vma vlook;
5921             size_t i, j, idx = 0;
5922 
5923             hlook = weaks;
5924             weaks = hlook->u.alias;
5925             hlook->u.alias = NULL;
5926 
5927             if (hlook->root.type != bfd_link_hash_defined
5928                 && hlook->root.type != bfd_link_hash_defweak)
5929               continue;
5930 
5931             slook = hlook->root.u.def.section;
5932             vlook = hlook->root.u.def.value;
5933 
5934             i = 0;
5935             j = sym_count;
5936             while (i != j)
5937               {
5938                 bfd_signed_vma vdiff;
5939                 idx = (i + j) / 2;
5940                 h = sorted_sym_hash[idx];
5941                 vdiff = vlook - h->root.u.def.value;
5942                 if (vdiff < 0)
5943                     j = idx;
5944                 else if (vdiff > 0)
5945                     i = idx + 1;
5946                 else
5947                     {
5948                       int sdiff = slook->id - h->root.u.def.section->id;
5949                       if (sdiff < 0)
5950                         j = idx;
5951                       else if (sdiff > 0)
5952                         i = idx + 1;
5953                       else
5954                         break;
5955                     }
5956               }
5957 
5958             /* We didn't find a value/section match.  */
5959             if (i == j)
5960               continue;
5961 
5962             /* With multiple aliases, or when the weak symbol is already
5963                strongly defined, we have multiple matching symbols and
5964                the binary search above may land on any of them.  Step
5965                one past the matching symbol(s).  */
5966             while (++idx != j)
5967               {
5968                 h = sorted_sym_hash[idx];
5969                 if (h->root.u.def.section != slook
5970                       || h->root.u.def.value != vlook)
5971                     break;
5972               }
5973 
5974             /* Now look back over the aliases.  Since we sorted by size
5975                as well as value and section, we'll choose the one with
5976                the largest size.  */
5977             while (idx-- != i)
5978               {
5979                 h = sorted_sym_hash[idx];
5980 
5981                 /* Stop if value or section doesn't match.  */
5982                 if (h->root.u.def.section != slook
5983                       || h->root.u.def.value != vlook)
5984                     break;
5985                 else if (h != hlook)
5986                     {
5987                       struct elf_link_hash_entry *t;
5988 
5989                       hlook->u.alias = h;
5990                       hlook->is_weakalias = 1;
5991                       t = h;
5992                       if (t->u.alias != NULL)
5993                         while (t->u.alias != h)
5994                           t = t->u.alias;
5995                       t->u.alias = hlook;
5996 
5997                       /* If the weak definition is in the list of dynamic
5998                          symbols, make sure the real definition is put
5999                          there as well.  */
6000                       if (hlook->dynindx != -1 && h->dynindx == -1)
6001                         {
6002                           if (! bfd_elf_link_record_dynamic_symbol (info, h))
6003                               {
6004                               err_free_sym_hash:
6005                                 free (sorted_sym_hash);
6006                                 goto error_return;
6007                               }
6008                         }
6009 
6010                       /* If the real definition is in the list of dynamic
6011                          symbols, make sure the weak definition is put
6012                          there as well.  If we don't do this, then the
6013                          dynamic loader might not merge the entries for the
6014                          real definition and the weak definition.  */
6015                       if (h->dynindx != -1 && hlook->dynindx == -1)
6016                         {
6017                           if (! bfd_elf_link_record_dynamic_symbol (info, hlook))
6018                               goto err_free_sym_hash;
6019                         }
6020                       break;
6021                     }
6022               }
6023           }
6024 
6025       free (sorted_sym_hash);
6026     }
6027 
6028   if (bed->check_directives
6029       && !(*bed->check_directives) (abfd, info))
6030     return false;
6031 
6032   /* If this is a non-traditional link, try to optimize the handling
6033      of the .stab/.stabstr sections.  */
6034   if (! dynamic
6035       && ! info->traditional_format
6036       && is_elf_hash_table (&htab->root)
6037       && (info->strip != strip_all && info->strip != strip_debugger))
6038     {
6039       asection *stabstr;
6040 
6041       stabstr = bfd_get_section_by_name (abfd, ".stabstr");
6042       if (stabstr != NULL)
6043           {
6044             bfd_size_type string_offset = 0;
6045             asection *stab;
6046 
6047             for (stab = abfd->sections; stab; stab = stab->next)
6048               if (startswith (stab->name, ".stab")
6049                     && (!stab->name[5] ||
6050                         (stab->name[5] == '.' && ISDIGIT (stab->name[6])))
6051                     && (stab->flags & SEC_MERGE) == 0
6052                     && !bfd_is_abs_section (stab->output_section))
6053                 {
6054                     struct bfd_elf_section_data *secdata;
6055 
6056                     secdata = elf_section_data (stab);
6057                     if (! _bfd_link_section_stabs (abfd, &htab->stab_info, stab,
6058                                                          stabstr, &secdata->sec_info,
6059                                                          &string_offset))
6060                       goto error_return;
6061                     if (secdata->sec_info)
6062                       stab->sec_info_type = SEC_INFO_TYPE_STABS;
6063               }
6064           }
6065     }
6066 
6067   if (dynamic && add_needed)
6068     {
6069       /* Add this bfd to the loaded list.  */
6070       struct elf_link_loaded_list *n;
6071 
6072       n = (struct elf_link_loaded_list *) bfd_alloc (abfd, sizeof (*n));
6073       if (n == NULL)
6074           goto error_return;
6075       n->abfd = abfd;
6076       n->next = htab->dyn_loaded;
6077       htab->dyn_loaded = n;
6078     }
6079   if (dynamic && !add_needed
6080       && (elf_dyn_lib_class (abfd) & DYN_DT_NEEDED) != 0)
6081     elf_dyn_lib_class (abfd) |= DYN_NO_NEEDED;
6082 
6083   return true;
6084 
6085  error_free_vers:
6086   free (old_tab);
6087   free (old_strtab);
6088   free (nondeflt_vers);
6089   free (extversym);
6090  error_free_sym:
6091   free (isymbuf);
6092  error_return:
6093   return false;
6094 }
6095 
6096 /* Return the linker hash table entry of a symbol that might be
6097    satisfied by an archive symbol.  Return -1 on error.  */
6098 
6099 struct bfd_link_hash_entry *
_bfd_elf_archive_symbol_lookup(bfd * abfd,struct bfd_link_info * info,const char * name)6100 _bfd_elf_archive_symbol_lookup (bfd *abfd,
6101                                         struct bfd_link_info *info,
6102                                         const char *name)
6103 {
6104   struct bfd_link_hash_entry *h;
6105   char *p, *copy;
6106   size_t len, first;
6107 
6108   h = bfd_link_hash_lookup (info->hash, name, false, false, true);
6109   if (h != NULL)
6110     return h;
6111 
6112   /* If this is a default version (the name contains @@), look up the
6113      symbol again with only one `@' as well as without the version.
6114      The effect is that references to the symbol with and without the
6115      version will be matched by the default symbol in the archive.  */
6116 
6117   p = strchr (name, ELF_VER_CHR);
6118   if (p == NULL || p[1] != ELF_VER_CHR)
6119     {
6120       /* Add this symbol to first hash if this archive has the first
6121            definition.  */
6122       if (is_elf_hash_table (info->hash))
6123           elf_link_add_to_first_hash (abfd, info, name, false);
6124       return h;
6125     }
6126 
6127   /* First check with only one `@'.  */
6128   len = strlen (name);
6129   copy = (char *) bfd_alloc (abfd, len);
6130   if (copy == NULL)
6131     return (struct bfd_link_hash_entry *) -1;
6132 
6133   first = p - name + 1;
6134   memcpy (copy, name, first);
6135   memcpy (copy + first, name + first + 1, len - first);
6136 
6137   h = bfd_link_hash_lookup (info->hash, copy, false, false, true);
6138   if (h == NULL)
6139     {
6140       /* We also need to check references to the symbol without the
6141            version.  */
6142       copy[first - 1] = '\0';
6143       h = bfd_link_hash_lookup (info->hash, copy, false, false, true);
6144     }
6145 
6146   bfd_release (abfd, copy);
6147   return h;
6148 }
6149 
6150 /* Add symbols from an ELF archive file to the linker hash table.  We
6151    don't use _bfd_generic_link_add_archive_symbols because we need to
6152    handle versioned symbols.
6153 
6154    Fortunately, ELF archive handling is simpler than that done by
6155    _bfd_generic_link_add_archive_symbols, which has to allow for a.out
6156    oddities.  In ELF, if we find a symbol in the archive map, and the
6157    symbol is currently undefined, we know that we must pull in that
6158    object file.
6159 
6160    Unfortunately, we do have to make multiple passes over the symbol
6161    table until nothing further is resolved.  */
6162 
6163 static bool
elf_link_add_archive_symbols(bfd * abfd,struct bfd_link_info * info)6164 elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
6165 {
6166   symindex c;
6167   unsigned char *included = NULL;
6168   carsym *symdefs;
6169   bool loop;
6170   size_t amt;
6171   const struct elf_backend_data *bed;
6172   struct bfd_link_hash_entry * (*archive_symbol_lookup)
6173     (bfd *, struct bfd_link_info *, const char *);
6174 
6175   if (! bfd_has_map (abfd))
6176     {
6177       /* An empty archive is a special case.  */
6178       if (bfd_openr_next_archived_file (abfd, NULL) == NULL)
6179           return true;
6180       bfd_set_error (bfd_error_no_armap);
6181       return false;
6182     }
6183 
6184   /* Keep track of all symbols we know to be already defined, and all
6185      files we know to be already included.  This is to speed up the
6186      second and subsequent passes.  */
6187   c = bfd_ardata (abfd)->symdef_count;
6188   if (c == 0)
6189     return true;
6190   amt = c * sizeof (*included);
6191   included = (unsigned char *) bfd_zmalloc (amt);
6192   if (included == NULL)
6193     return false;
6194 
6195   symdefs = bfd_ardata (abfd)->symdefs;
6196   bed = get_elf_backend_data (abfd);
6197   archive_symbol_lookup = bed->elf_backend_archive_symbol_lookup;
6198 
6199   do
6200     {
6201       file_ptr last;
6202       symindex i;
6203       carsym *symdef;
6204       carsym *symdefend;
6205 
6206       loop = false;
6207       last = -1;
6208 
6209       symdef = symdefs;
6210       symdefend = symdef + c;
6211       for (i = 0; symdef < symdefend; symdef++, i++)
6212           {
6213             struct bfd_link_hash_entry *h;
6214             bfd *element;
6215             struct bfd_link_hash_entry *undefs_tail;
6216             symindex mark;
6217 
6218             if (included[i])
6219               continue;
6220             if (symdef->file_offset == last)
6221               {
6222                 included[i] = true;
6223                 continue;
6224               }
6225 
6226             h = archive_symbol_lookup (abfd, info, symdef->name);
6227             if (h == (struct bfd_link_hash_entry *) -1)
6228               goto error_return;
6229 
6230             if (h == NULL)
6231               continue;
6232 
6233             if (h->type == bfd_link_hash_undefined)
6234               {
6235                 /* If the archive element has already been loaded then one
6236                      of the symbols defined by that element might have been
6237                      made undefined due to being in a discarded section.  */
6238                 if (is_elf_hash_table (info->hash)
6239                       && ((struct elf_link_hash_entry *) h)->indx == -3)
6240                     continue;
6241               }
6242             else if (h->type == bfd_link_hash_common)
6243               {
6244                 /* We currently have a common symbol.  The archive map contains
6245                      a reference to this symbol, so we may want to include it.  We
6246                      only want to include it however, if this archive element
6247                      contains a definition of the symbol, not just another common
6248                      declaration of it.
6249 
6250                      Unfortunately some archivers (including GNU ar) will put
6251                      declarations of common symbols into their archive maps, as
6252                      well as real definitions, so we cannot just go by the archive
6253                      map alone.  Instead we must read in the element's symbol
6254                      table and check that to see what kind of symbol definition
6255                      this is.  */
6256                 if (! elf_link_is_defined_archive_symbol (abfd, symdef))
6257                     continue;
6258               }
6259             else
6260               {
6261                 if (h->type != bfd_link_hash_undefweak)
6262                     /* Symbol must be defined.  Don't check it again.  */
6263                     included[i] = true;
6264 
6265                 if (!is_elf_hash_table (info->hash))
6266                     continue;
6267                 struct elf_link_hash_entry *eh
6268                     = (struct elf_link_hash_entry *) h;
6269                 /* Ignore the archive if the symbol isn't referenced by a
6270                      regular object or isn't defined in a shared object.  */
6271                 if (!eh->ref_regular || !eh->def_dynamic)
6272                     continue;
6273                 /* Ignore the dynamic definition if symbol is first
6274                      defined in this archive.  */
6275                 struct elf_link_hash_table *htab = elf_hash_table (info);
6276                 if (htab->first_hash == NULL)
6277                     continue;
6278                 struct elf_link_first_hash_entry *e
6279                     = ((struct elf_link_first_hash_entry *)
6280                        bfd_hash_lookup (htab->first_hash, symdef->name,
6281                                             false, false));
6282                 if (e == NULL || e->abfd != abfd)
6283                     continue;
6284               }
6285 
6286             /* We need to include this archive member.  */
6287             element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset,
6288                                                        info);
6289             if (element == NULL)
6290               goto error_return;
6291 
6292             if (! bfd_check_format (element, bfd_object))
6293               goto error_return;
6294 
6295             undefs_tail = info->hash->undefs_tail;
6296 
6297             if (!(*info->callbacks
6298                     ->add_archive_element) (info, element, symdef->name, &element))
6299               continue;
6300             if (!bfd_link_add_symbols (element, info))
6301               goto error_return;
6302 
6303             /* If there are any new undefined symbols, we need to make
6304                another pass through the archive in order to see whether
6305                they can be defined.  FIXME: This isn't perfect, because
6306                common symbols wind up on undefs_tail and because an
6307                undefined symbol which is defined later on in this pass
6308                does not require another pass.  This isn't a bug, but it
6309                does make the code less efficient than it could be.  */
6310             if (undefs_tail != info->hash->undefs_tail)
6311               loop = true;
6312 
6313             /* Look backward to mark all symbols from this object file
6314                which we have already seen in this pass.  */
6315             mark = i;
6316             do
6317               {
6318                 included[mark] = true;
6319                 if (mark == 0)
6320                     break;
6321                 --mark;
6322               }
6323             while (symdefs[mark].file_offset == symdef->file_offset);
6324 
6325             /* We mark subsequent symbols from this object file as we go
6326                on through the loop.  */
6327             last = symdef->file_offset;
6328           }
6329     }
6330   while (loop);
6331 
6332   free (included);
6333   return true;
6334 
6335  error_return:
6336   free (included);
6337   return false;
6338 }
6339 
6340 /* Given an ELF BFD, add symbols to the global hash table as
6341    appropriate.  */
6342 
6343 bool
bfd_elf_link_add_symbols(bfd * abfd,struct bfd_link_info * info)6344 bfd_elf_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
6345 {
6346   switch (bfd_get_format (abfd))
6347     {
6348     case bfd_object:
6349       return elf_link_add_object_symbols (abfd, info);
6350     case bfd_archive:
6351       return elf_link_add_archive_symbols (abfd, info);
6352     default:
6353       bfd_set_error (bfd_error_wrong_format);
6354       return false;
6355     }
6356 }
6357 
6358 struct hash_codes_info
6359 {
6360   unsigned long *hashcodes;
6361   bool error;
6362 };
6363 
6364 /* This function will be called though elf_link_hash_traverse to store
6365    all hash value of the exported symbols in an array.  */
6366 
6367 static bool
elf_collect_hash_codes(struct elf_link_hash_entry * h,void * data)6368 elf_collect_hash_codes (struct elf_link_hash_entry *h, void *data)
6369 {
6370   struct hash_codes_info *inf = (struct hash_codes_info *) data;
6371   const char *name;
6372   unsigned long ha;
6373   char *alc = NULL;
6374 
6375   /* Ignore indirect symbols.  These are added by the versioning code.  */
6376   if (h->dynindx == -1)
6377     return true;
6378 
6379   name = h->root.root.string;
6380   if (h->versioned >= versioned)
6381     {
6382       char *p = strchr (name, ELF_VER_CHR);
6383       if (p != NULL)
6384           {
6385             alc = (char *) bfd_malloc (p - name + 1);
6386             if (alc == NULL)
6387               {
6388                 inf->error = true;
6389                 return false;
6390               }
6391             memcpy (alc, name, p - name);
6392             alc[p - name] = '\0';
6393             name = alc;
6394           }
6395     }
6396 
6397   /* Compute the hash value.  */
6398   ha = bfd_elf_hash (name);
6399 
6400   /* Store the found hash value in the array given as the argument.  */
6401   *(inf->hashcodes)++ = ha;
6402 
6403   /* And store it in the struct so that we can put it in the hash table
6404      later.  */
6405   h->u.elf_hash_value = ha;
6406 
6407   free (alc);
6408   return true;
6409 }
6410 
6411 struct collect_gnu_hash_codes
6412 {
6413   bfd *output_bfd;
6414   const struct elf_backend_data *bed;
6415   unsigned long int nsyms;
6416   unsigned long int maskbits;
6417   unsigned long int *hashcodes;
6418   unsigned long int *hashval;
6419   unsigned long int *indx;
6420   unsigned long int *counts;
6421   bfd_vma *bitmask;
6422   bfd_byte *contents;
6423   bfd_size_type xlat;
6424   long int min_dynindx;
6425   unsigned long int bucketcount;
6426   unsigned long int symindx;
6427   long int local_indx;
6428   long int shift1, shift2;
6429   unsigned long int mask;
6430   bool error;
6431 };
6432 
6433 /* This function will be called though elf_link_hash_traverse to store
6434    all hash value of the exported symbols in an array.  */
6435 
6436 static bool
elf_collect_gnu_hash_codes(struct elf_link_hash_entry * h,void * data)6437 elf_collect_gnu_hash_codes (struct elf_link_hash_entry *h, void *data)
6438 {
6439   struct collect_gnu_hash_codes *s = (struct collect_gnu_hash_codes *) data;
6440   const char *name;
6441   unsigned long ha;
6442   char *alc = NULL;
6443 
6444   /* Ignore indirect symbols.  These are added by the versioning code.  */
6445   if (h->dynindx == -1)
6446     return true;
6447 
6448   /* Ignore also local symbols and undefined symbols.  */
6449   if (! (*s->bed->elf_hash_symbol) (h))
6450     return true;
6451 
6452   name = h->root.root.string;
6453   if (h->versioned >= versioned)
6454     {
6455       char *p = strchr (name, ELF_VER_CHR);
6456       if (p != NULL)
6457           {
6458             alc = (char *) bfd_malloc (p - name + 1);
6459             if (alc == NULL)
6460               {
6461                 s->error = true;
6462                 return false;
6463               }
6464             memcpy (alc, name, p - name);
6465             alc[p - name] = '\0';
6466             name = alc;
6467           }
6468     }
6469 
6470   /* Compute the hash value.  */
6471   ha = bfd_elf_gnu_hash (name);
6472 
6473   /* Store the found hash value in the array for compute_bucket_count,
6474      and also for .dynsym reordering purposes.  */
6475   s->hashcodes[s->nsyms] = ha;
6476   s->hashval[h->dynindx] = ha;
6477   ++s->nsyms;
6478   if (s->min_dynindx < 0 || s->min_dynindx > h->dynindx)
6479     s->min_dynindx = h->dynindx;
6480 
6481   free (alc);
6482   return true;
6483 }
6484 
6485 /* This function will be called though elf_link_hash_traverse to do
6486    final dynamic symbol renumbering in case of .gnu.hash.
6487    If using .MIPS.xhash, invoke record_xhash_symbol to add symbol index
6488    to the translation table.  */
6489 
6490 static bool
elf_gnu_hash_process_symidx(struct elf_link_hash_entry * h,void * data)6491 elf_gnu_hash_process_symidx (struct elf_link_hash_entry *h, void *data)
6492 {
6493   struct collect_gnu_hash_codes *s = (struct collect_gnu_hash_codes *) data;
6494   unsigned long int bucket;
6495   unsigned long int val;
6496 
6497   /* Ignore indirect symbols.  */
6498   if (h->dynindx == -1)
6499     return true;
6500 
6501   /* Ignore also local symbols and undefined symbols.  */
6502   if (! (*s->bed->elf_hash_symbol) (h))
6503     {
6504       if (h->dynindx >= s->min_dynindx)
6505           {
6506             if (s->bed->record_xhash_symbol != NULL)
6507               {
6508                 (*s->bed->record_xhash_symbol) (h, 0);
6509                 s->local_indx++;
6510               }
6511             else
6512               h->dynindx = s->local_indx++;
6513           }
6514       return true;
6515     }
6516 
6517   bucket = s->hashval[h->dynindx] % s->bucketcount;
6518   val = (s->hashval[h->dynindx] >> s->shift1)
6519           & ((s->maskbits >> s->shift1) - 1);
6520   s->bitmask[val] |= ((bfd_vma) 1) << (s->hashval[h->dynindx] & s->mask);
6521   s->bitmask[val]
6522     |= ((bfd_vma) 1) << ((s->hashval[h->dynindx] >> s->shift2) & s->mask);
6523   val = s->hashval[h->dynindx] & ~(unsigned long int) 1;
6524   if (s->counts[bucket] == 1)
6525     /* Last element terminates the chain.  */
6526     val |= 1;
6527   bfd_put_32 (s->output_bfd, val,
6528                 s->contents + (s->indx[bucket] - s->symindx) * 4);
6529   --s->counts[bucket];
6530   if (s->bed->record_xhash_symbol != NULL)
6531     {
6532       bfd_vma xlat_loc = s->xlat + (s->indx[bucket]++ - s->symindx) * 4;
6533 
6534       (*s->bed->record_xhash_symbol) (h, xlat_loc);
6535     }
6536   else
6537     h->dynindx = s->indx[bucket]++;
6538   return true;
6539 }
6540 
6541 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section.  */
6542 
6543 bool
_bfd_elf_hash_symbol(struct elf_link_hash_entry * h)6544 _bfd_elf_hash_symbol (struct elf_link_hash_entry *h)
6545 {
6546   return !(h->forced_local
6547              || h->root.type == bfd_link_hash_undefined
6548              || h->root.type == bfd_link_hash_undefweak
6549              || ((h->root.type == bfd_link_hash_defined
6550                     || h->root.type == bfd_link_hash_defweak)
6551                  && h->root.u.def.section->output_section == NULL));
6552 }
6553 
6554 /* Array used to determine the number of hash table buckets to use
6555    based on the number of symbols there are.  If there are fewer than
6556    3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
6557    fewer than 37 we use 17 buckets, and so forth.  We never use more
6558    than 32771 buckets.  */
6559 
6560 static const size_t elf_buckets[] =
6561 {
6562   1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
6563   16411, 32771, 0
6564 };
6565 
6566 /* Compute bucket count for hashing table.  We do not use a static set
6567    of possible tables sizes anymore.  Instead we determine for all
6568    possible reasonable sizes of the table the outcome (i.e., the
6569    number of collisions etc) and choose the best solution.  The
6570    weighting functions are not too simple to allow the table to grow
6571    without bounds.  Instead one of the weighting factors is the size.
6572    Therefore the result is always a good payoff between few collisions
6573    (= short chain lengths) and table size.  */
6574 static size_t
compute_bucket_count(struct bfd_link_info * info ATTRIBUTE_UNUSED,unsigned long int * hashcodes ATTRIBUTE_UNUSED,unsigned long int nsyms,int gnu_hash)6575 compute_bucket_count (struct bfd_link_info *info ATTRIBUTE_UNUSED,
6576                           unsigned long int *hashcodes ATTRIBUTE_UNUSED,
6577                           unsigned long int nsyms,
6578                           int gnu_hash)
6579 {
6580   size_t best_size = 0;
6581   unsigned long int i;
6582 
6583   if (info->optimize)
6584     {
6585       size_t minsize;
6586       size_t maxsize;
6587       uint64_t best_chlen = ~((uint64_t) 0);
6588       bfd *dynobj = elf_hash_table (info)->dynobj;
6589       size_t dynsymcount = elf_hash_table (info)->dynsymcount;
6590       const struct elf_backend_data *bed = get_elf_backend_data (dynobj);
6591       unsigned long int *counts;
6592       bfd_size_type amt;
6593       unsigned int no_improvement_count = 0;
6594 
6595       /* Possible optimization parameters: if we have NSYMS symbols we say
6596            that the hashing table must at least have NSYMS/4 and at most
6597            2*NSYMS buckets.  */
6598       minsize = nsyms / 4;
6599       if (minsize == 0)
6600           minsize = 1;
6601       best_size = maxsize = nsyms * 2;
6602       if (gnu_hash)
6603           {
6604             if (minsize < 2)
6605               minsize = 2;
6606             if ((best_size & 31) == 0)
6607               ++best_size;
6608           }
6609 
6610       /* Create array where we count the collisions in.  We must use bfd_malloc
6611            since the size could be large.  */
6612       amt = maxsize;
6613       amt *= sizeof (unsigned long int);
6614       counts = (unsigned long int *) bfd_malloc (amt);
6615       if (counts == NULL)
6616           return 0;
6617 
6618       /* Compute the "optimal" size for the hash table.  The criteria is a
6619            minimal chain length.  The minor criteria is (of course) the size
6620            of the table.  */
6621       for (i = minsize; i < maxsize; ++i)
6622           {
6623             /* Walk through the array of hashcodes and count the collisions.  */
6624             uint64_t max;
6625             unsigned long int j;
6626             unsigned long int fact;
6627 
6628             if (gnu_hash && (i & 31) == 0)
6629               continue;
6630 
6631             memset (counts, '\0', i * sizeof (unsigned long int));
6632 
6633             /* Determine how often each hash bucket is used.  */
6634             for (j = 0; j < nsyms; ++j)
6635               ++counts[hashcodes[j] % i];
6636 
6637             /* For the weight function we need some information about the
6638                pagesize on the target.  This is information need not be 100%
6639                accurate.  Since this information is not available (so far) we
6640                define it here to a reasonable default value.  If it is crucial
6641                to have a better value some day simply define this value.  */
6642 # ifndef BFD_TARGET_PAGESIZE
6643 #  define BFD_TARGET_PAGESIZE (4096)
6644 # endif
6645 
6646             /* We in any case need 2 + DYNSYMCOUNT entries for the size values
6647                and the chains.  */
6648             max = (2 + dynsymcount) * bed->s->sizeof_hash_entry;
6649 
6650 # if 1
6651             /* Variant 1: optimize for short chains.  We add the squares
6652                of all the chain lengths (which favors many small chain
6653                over a few long chains).  */
6654             for (j = 0; j < i; ++j)
6655               max += counts[j] * counts[j];
6656 
6657             /* This adds penalties for the overall size of the table.  */
6658             fact = i / (BFD_TARGET_PAGESIZE / bed->s->sizeof_hash_entry) + 1;
6659             max *= fact * fact;
6660 # else
6661             /* Variant 2: Optimize a lot more for small table.  Here we
6662                also add squares of the size but we also add penalties for
6663                empty slots (the +1 term).  */
6664             for (j = 0; j < i; ++j)
6665               max += (1 + counts[j]) * (1 + counts[j]);
6666 
6667             /* The overall size of the table is considered, but not as
6668                strong as in variant 1, where it is squared.  */
6669             fact = i / (BFD_TARGET_PAGESIZE / bed->s->sizeof_hash_entry) + 1;
6670             max *= fact;
6671 # endif
6672 
6673             /* Compare with current best results.  */
6674             if (max < best_chlen)
6675               {
6676                 best_chlen = max;
6677                 best_size = i;
6678                 no_improvement_count = 0;
6679               }
6680             /* PR 11843: Avoid futile long searches for the best bucket size
6681                when there are a large number of symbols.  */
6682             else if (++no_improvement_count == 100)
6683               break;
6684           }
6685 
6686       free (counts);
6687     }
6688   else
6689     {
6690       for (i = 0; elf_buckets[i] != 0; i++)
6691           {
6692             best_size = elf_buckets[i];
6693             if (nsyms < elf_buckets[i + 1])
6694               break;
6695           }
6696       if (gnu_hash && best_size < 2)
6697           best_size = 2;
6698     }
6699 
6700   return best_size;
6701 }
6702 
6703 /* Size any SHT_GROUP section for ld -r.  */
6704 
6705 bool
_bfd_elf_size_group_sections(struct bfd_link_info * info)6706 _bfd_elf_size_group_sections (struct bfd_link_info *info)
6707 {
6708   bfd *ibfd;
6709   asection *s;
6710 
6711   for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
6712     if (bfd_get_flavour (ibfd) == bfd_target_elf_flavour
6713           && (s = ibfd->sections) != NULL
6714           && s->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
6715           && !_bfd_elf_fixup_group_sections (ibfd, bfd_abs_section_ptr))
6716       return false;
6717   return true;
6718 }
6719 
6720 /* Set a default stack segment size.  The value in INFO wins.  If it
6721    is unset, LEGACY_SYMBOL's value is used, and if that symbol is
6722    undefined it is initialized.  */
6723 
6724 bool
bfd_elf_stack_segment_size(bfd * output_bfd,struct bfd_link_info * info,const char * legacy_symbol,bfd_vma default_size)6725 bfd_elf_stack_segment_size (bfd *output_bfd,
6726                                   struct bfd_link_info *info,
6727                                   const char *legacy_symbol,
6728                                   bfd_vma default_size)
6729 {
6730   struct elf_link_hash_entry *h = NULL;
6731 
6732   /* Look for legacy symbol.  */
6733   if (legacy_symbol)
6734     h = elf_link_hash_lookup (elf_hash_table (info), legacy_symbol,
6735                                     false, false, false);
6736   if (h && (h->root.type == bfd_link_hash_defined
6737               || h->root.type == bfd_link_hash_defweak)
6738       && h->def_regular
6739       && (h->type == STT_NOTYPE || h->type == STT_OBJECT))
6740     {
6741       /* The symbol has no type if specified on the command line.  */
6742       h->type = STT_OBJECT;
6743       if (info->stacksize)
6744           /* xgettext:c-format */
6745           _bfd_error_handler (_("%pB: stack size specified and %s set"),
6746                                   output_bfd, legacy_symbol);
6747       else if (h->root.u.def.section != bfd_abs_section_ptr)
6748           /* xgettext:c-format */
6749           _bfd_error_handler (_("%pB: %s not absolute"),
6750                                   output_bfd, legacy_symbol);
6751       else
6752           info->stacksize = h->root.u.def.value;
6753     }
6754 
6755   if (!info->stacksize)
6756     /* If the user didn't set a size, or explicitly inhibit the
6757        size, set it now.  */
6758     info->stacksize = default_size;
6759 
6760   /* Provide the legacy symbol, if it is referenced.  */
6761   if (h && (h->root.type == bfd_link_hash_undefined
6762               || h->root.type == bfd_link_hash_undefweak))
6763     {
6764       struct bfd_link_hash_entry *bh = NULL;
6765 
6766       if (!(_bfd_generic_link_add_one_symbol
6767               (info, output_bfd, legacy_symbol,
6768                BSF_GLOBAL, bfd_abs_section_ptr,
6769                info->stacksize >= 0 ? info->stacksize : 0,
6770                NULL, false, get_elf_backend_data (output_bfd)->collect, &bh)))
6771           return false;
6772 
6773       h = (struct elf_link_hash_entry *) bh;
6774       h->def_regular = 1;
6775       h->type = STT_OBJECT;
6776     }
6777 
6778   return true;
6779 }
6780 
6781 /* Sweep symbols in swept sections.  Called via elf_link_hash_traverse.  */
6782 
6783 struct elf_gc_sweep_symbol_info
6784 {
6785   struct bfd_link_info *info;
6786   void (*hide_symbol) (struct bfd_link_info *, struct elf_link_hash_entry *,
6787                            bool);
6788 };
6789 
6790 static bool
elf_gc_sweep_symbol(struct elf_link_hash_entry * h,void * data)6791 elf_gc_sweep_symbol (struct elf_link_hash_entry *h, void *data)
6792 {
6793   if (!h->mark
6794       && (((h->root.type == bfd_link_hash_defined
6795               || h->root.type == bfd_link_hash_defweak)
6796              && !((h->def_regular || ELF_COMMON_DEF_P (h))
6797                     && h->root.u.def.section->gc_mark))
6798             || h->root.type == bfd_link_hash_undefined
6799             || h->root.type == bfd_link_hash_undefweak))
6800     {
6801       struct elf_gc_sweep_symbol_info *inf;
6802 
6803       inf = (struct elf_gc_sweep_symbol_info *) data;
6804       (*inf->hide_symbol) (inf->info, h, true);
6805       h->def_regular = 0;
6806       h->ref_regular = 0;
6807       h->ref_regular_nonweak = 0;
6808     }
6809 
6810   return true;
6811 }
6812 
6813 /* Set up the sizes and contents of the ELF dynamic sections.  This is
6814    called by the ELF linker emulation before_allocation routine.  We
6815    must set the sizes of the sections before the linker sets the
6816    addresses of the various sections.  */
6817 
6818 bool
bfd_elf_size_dynamic_sections(bfd * output_bfd,const char * soname,const char * rpath,const char * filter_shlib,const char * audit,const char * depaudit,const char * const * auxiliary_filters,struct bfd_link_info * info,asection ** sinterpptr)6819 bfd_elf_size_dynamic_sections (bfd *output_bfd,
6820                                      const char *soname,
6821                                      const char *rpath,
6822                                      const char *filter_shlib,
6823                                      const char *audit,
6824                                      const char *depaudit,
6825                                      const char * const *auxiliary_filters,
6826                                      struct bfd_link_info *info,
6827                                      asection **sinterpptr)
6828 {
6829   bfd *dynobj;
6830   const struct elf_backend_data *bed;
6831 
6832   *sinterpptr = NULL;
6833 
6834   if (!is_elf_hash_table (info->hash))
6835     return true;
6836 
6837   /* Any syms created from now on start with -1 in
6838      got.refcount/offset and plt.refcount/offset.  */
6839   elf_hash_table (info)->init_got_refcount
6840     = elf_hash_table (info)->init_got_offset;
6841   elf_hash_table (info)->init_plt_refcount
6842     = elf_hash_table (info)->init_plt_offset;
6843 
6844   bed = get_elf_backend_data (output_bfd);
6845 
6846   /* The backend may have to create some sections regardless of whether
6847      we're dynamic or not.  */
6848   if (bed->elf_backend_early_size_sections
6849       && !bed->elf_backend_early_size_sections (output_bfd, info))
6850     return false;
6851 
6852   dynobj = elf_hash_table (info)->dynobj;
6853 
6854   if (dynobj != NULL && elf_hash_table (info)->dynamic_sections_created)
6855     {
6856       struct bfd_elf_version_tree *verdefs;
6857       struct elf_info_failed asvinfo;
6858       struct bfd_elf_version_tree *t;
6859       struct bfd_elf_version_expr *d;
6860       asection *s;
6861       size_t soname_indx;
6862 
6863       /* If we are supposed to export all symbols into the dynamic symbol
6864            table (this is not the normal case), then do so.  */
6865       if (info->export_dynamic
6866             || (bfd_link_executable (info) && info->dynamic))
6867           {
6868             struct elf_info_failed eif;
6869 
6870             eif.info = info;
6871             eif.failed = false;
6872             elf_link_hash_traverse (elf_hash_table (info),
6873                                           _bfd_elf_export_symbol,
6874                                           &eif);
6875             if (eif.failed)
6876               return false;
6877           }
6878 
6879       if (soname != NULL)
6880           {
6881             soname_indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
6882                                                        soname, true);
6883             if (soname_indx == (size_t) -1
6884                 || !_bfd_elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
6885               return false;
6886           }
6887       else
6888           soname_indx = (size_t) -1;
6889 
6890       /* Make all global versions with definition.  */
6891       for (t = info->version_info; t != NULL; t = t->next)
6892           for (d = t->globals.list; d != NULL; d = d->next)
6893             if (!d->symver && d->literal)
6894               {
6895                 const char *verstr, *name;
6896                 size_t namelen, verlen, newlen;
6897                 char *newname, *p, leading_char;
6898                 struct elf_link_hash_entry *newh;
6899 
6900                 leading_char = bfd_get_symbol_leading_char (output_bfd);
6901                 name = d->pattern;
6902                 namelen = strlen (name) + (leading_char != '\0');
6903                 verstr = t->name;
6904                 verlen = strlen (verstr);
6905                 newlen = namelen + verlen + 3;
6906 
6907                 newname = (char *) bfd_malloc (newlen);
6908                 if (newname == NULL)
6909                     return false;
6910                 newname[0] = leading_char;
6911                 memcpy (newname + (leading_char != '\0'), name, namelen);
6912 
6913                 /* Check the hidden versioned definition.  */
6914                 p = newname + namelen;
6915                 *p++ = ELF_VER_CHR;
6916                 memcpy (p, verstr, verlen + 1);
6917                 newh = elf_link_hash_lookup (elf_hash_table (info),
6918                                                      newname, false, false,
6919                                                      false);
6920                 if (newh == NULL
6921                       || (newh->root.type != bfd_link_hash_defined
6922                           && newh->root.type != bfd_link_hash_defweak))
6923                     {
6924                       /* Check the default versioned definition.  */
6925                       *p++ = ELF_VER_CHR;
6926                       memcpy (p, verstr, verlen + 1);
6927                       newh = elf_link_hash_lookup (elf_hash_table (info),
6928                                                          newname, false, false,
6929                                                          false);
6930                     }
6931                 free (newname);
6932 
6933                 /* Mark this version if there is a definition and it is
6934                      not defined in a shared object.  */
6935                 if (newh != NULL
6936                       && !newh->def_dynamic
6937                       && (newh->root.type == bfd_link_hash_defined
6938                           || newh->root.type == bfd_link_hash_defweak))
6939                     d->symver = 1;
6940               }
6941 
6942       /* Attach all the symbols to their version information.  */
6943       asvinfo.info = info;
6944       asvinfo.failed = false;
6945 
6946       elf_link_hash_traverse (elf_hash_table (info),
6947                                     _bfd_elf_link_assign_sym_version,
6948                                     &asvinfo);
6949       if (asvinfo.failed)
6950           return false;
6951 
6952       if (!info->allow_undefined_version)
6953           {
6954             /* Check if all global versions have a definition.  */
6955             bool all_defined = true;
6956             for (t = info->version_info; t != NULL; t = t->next)
6957               for (d = t->globals.list; d != NULL; d = d->next)
6958                 if (d->literal && !d->symver && !d->script)
6959                     {
6960                       _bfd_error_handler
6961                         (_("%s: undefined version: %s"),
6962                          d->pattern, t->name);
6963                       all_defined = false;
6964                     }
6965 
6966             if (!all_defined)
6967               {
6968                 bfd_set_error (bfd_error_bad_value);
6969                 return false;
6970               }
6971           }
6972 
6973       /* Set up the version definition section.  */
6974       s = bfd_get_linker_section (dynobj, ".gnu.version_d");
6975       BFD_ASSERT (s != NULL);
6976 
6977       /* We may have created additional version definitions if we are
6978            just linking a regular application.  */
6979       verdefs = info->version_info;
6980 
6981       /* Skip anonymous version tag.  */
6982       if (verdefs != NULL && verdefs->vernum == 0)
6983           verdefs = verdefs->next;
6984 
6985       if (verdefs == NULL && !info->create_default_symver)
6986           s->flags |= SEC_EXCLUDE;
6987       else
6988           {
6989             unsigned int cdefs;
6990             bfd_size_type size;
6991             bfd_byte *p;
6992             Elf_Internal_Verdef def;
6993             Elf_Internal_Verdaux defaux;
6994             struct bfd_link_hash_entry *bh;
6995             struct elf_link_hash_entry *h;
6996             const char *name;
6997 
6998             cdefs = 0;
6999             size = 0;
7000 
7001             /* Make space for the base version.  */
7002             size += sizeof (Elf_External_Verdef);
7003             size += sizeof (Elf_External_Verdaux);
7004             ++cdefs;
7005 
7006             /* Make space for the default version.  */
7007             if (info->create_default_symver)
7008               {
7009                 size += sizeof (Elf_External_Verdef);
7010                 ++cdefs;
7011               }
7012 
7013             for (t = verdefs; t != NULL; t = t->next)
7014               {
7015                 struct bfd_elf_version_deps *n;
7016 
7017                 /* Don't emit base version twice.  */
7018                 if (t->vernum == 0)
7019                     continue;
7020 
7021                 size += sizeof (Elf_External_Verdef);
7022                 size += sizeof (Elf_External_Verdaux);
7023                 ++cdefs;
7024 
7025                 for (n = t->deps; n != NULL; n = n->next)
7026                     size += sizeof (Elf_External_Verdaux);
7027               }
7028 
7029             s->size = size;
7030             s->contents = (unsigned char *) bfd_alloc (output_bfd, s->size);
7031             if (s->contents == NULL && s->size != 0)
7032               return false;
7033 
7034             /* Fill in the version definition section.  */
7035 
7036             p = s->contents;
7037 
7038             def.vd_version = VER_DEF_CURRENT;
7039             def.vd_flags = VER_FLG_BASE;
7040             def.vd_ndx = 1;
7041             def.vd_cnt = 1;
7042             if (info->create_default_symver)
7043               {
7044                 def.vd_aux = 2 * sizeof (Elf_External_Verdef);
7045                 def.vd_next = sizeof (Elf_External_Verdef);
7046               }
7047             else
7048               {
7049                 def.vd_aux = sizeof (Elf_External_Verdef);
7050                 def.vd_next = (sizeof (Elf_External_Verdef)
7051                                    + sizeof (Elf_External_Verdaux));
7052               }
7053 
7054             if (soname_indx != (size_t) -1)
7055               {
7056                 _bfd_elf_strtab_addref (elf_hash_table (info)->dynstr,
7057                                               soname_indx);
7058                 def.vd_hash = bfd_elf_hash (soname);
7059                 defaux.vda_name = soname_indx;
7060                 name = soname;
7061               }
7062             else
7063               {
7064                 size_t indx;
7065 
7066                 name = lbasename (bfd_get_filename (output_bfd));
7067                 def.vd_hash = bfd_elf_hash (name);
7068                 indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
7069                                                     name, false);
7070                 if (indx == (size_t) -1)
7071                     return false;
7072                 defaux.vda_name = indx;
7073               }
7074             defaux.vda_next = 0;
7075 
7076             _bfd_elf_swap_verdef_out (output_bfd, &def,
7077                                             (Elf_External_Verdef *) p);
7078             p += sizeof (Elf_External_Verdef);
7079             if (info->create_default_symver)
7080               {
7081                 /* Add a symbol representing this version.  */
7082                 bh = NULL;
7083                 if (! (_bfd_generic_link_add_one_symbol
7084                          (info, dynobj, name, BSF_GLOBAL, bfd_abs_section_ptr,
7085                           0, NULL, false,
7086                           get_elf_backend_data (dynobj)->collect, &bh)))
7087                     return false;
7088                 h = (struct elf_link_hash_entry *) bh;
7089                 h->non_elf = 0;
7090                 h->def_regular = 1;
7091                 h->type = STT_OBJECT;
7092                 h->verinfo.vertree = NULL;
7093 
7094                 if (! bfd_elf_link_record_dynamic_symbol (info, h))
7095                     return false;
7096 
7097                 /* Create a duplicate of the base version with the same
7098                      aux block, but different flags.  */
7099                 def.vd_flags = 0;
7100                 def.vd_ndx = 2;
7101                 def.vd_aux = sizeof (Elf_External_Verdef);
7102                 if (verdefs)
7103                     def.vd_next = (sizeof (Elf_External_Verdef)
7104                                      + sizeof (Elf_External_Verdaux));
7105                 else
7106                     def.vd_next = 0;
7107                 _bfd_elf_swap_verdef_out (output_bfd, &def,
7108                                                   (Elf_External_Verdef *) p);
7109                 p += sizeof (Elf_External_Verdef);
7110               }
7111             _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
7112                                              (Elf_External_Verdaux *) p);
7113             p += sizeof (Elf_External_Verdaux);
7114 
7115             for (t = verdefs; t != NULL; t = t->next)
7116               {
7117                 unsigned int cdeps;
7118                 struct bfd_elf_version_deps *n;
7119 
7120                 /* Don't emit the base version twice.  */
7121                 if (t->vernum == 0)
7122                     continue;
7123 
7124                 cdeps = 0;
7125                 for (n = t->deps; n != NULL; n = n->next)
7126                     ++cdeps;
7127 
7128                 /* Add a symbol representing this version.  */
7129                 bh = NULL;
7130                 if (! (_bfd_generic_link_add_one_symbol
7131                          (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
7132                           0, NULL, false,
7133                           get_elf_backend_data (dynobj)->collect, &bh)))
7134                     return false;
7135                 h = (struct elf_link_hash_entry *) bh;
7136                 h->non_elf = 0;
7137                 h->def_regular = 1;
7138                 h->type = STT_OBJECT;
7139                 h->verinfo.vertree = t;
7140 
7141                 if (! bfd_elf_link_record_dynamic_symbol (info, h))
7142                     return false;
7143 
7144                 def.vd_version = VER_DEF_CURRENT;
7145                 def.vd_flags = 0;
7146                 if (t->globals.list == NULL
7147                       && t->locals.list == NULL
7148                       && ! t->used)
7149                     def.vd_flags |= VER_FLG_WEAK;
7150                 def.vd_ndx = t->vernum + (info->create_default_symver ? 2 : 1);
7151                 def.vd_cnt = cdeps + 1;
7152                 def.vd_hash = bfd_elf_hash (t->name);
7153                 def.vd_aux = sizeof (Elf_External_Verdef);
7154                 def.vd_next = 0;
7155 
7156                 /* If a basever node is next, it *must* be the last node in
7157                      the chain, otherwise Verdef construction breaks.  */
7158                 if (t->next != NULL && t->next->vernum == 0)
7159                     BFD_ASSERT (t->next->next == NULL);
7160 
7161                 if (t->next != NULL && t->next->vernum != 0)
7162                     def.vd_next = (sizeof (Elf_External_Verdef)
7163                                      + (cdeps + 1) * sizeof (Elf_External_Verdaux));
7164 
7165                 _bfd_elf_swap_verdef_out (output_bfd, &def,
7166                                                   (Elf_External_Verdef *) p);
7167                 p += sizeof (Elf_External_Verdef);
7168 
7169                 defaux.vda_name = h->dynstr_index;
7170                 _bfd_elf_strtab_addref (elf_hash_table (info)->dynstr,
7171                                               h->dynstr_index);
7172                 defaux.vda_next = 0;
7173                 if (t->deps != NULL)
7174                     defaux.vda_next = sizeof (Elf_External_Verdaux);
7175                 t->name_indx = defaux.vda_name;
7176 
7177                 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
7178                                                    (Elf_External_Verdaux *) p);
7179                 p += sizeof (Elf_External_Verdaux);
7180 
7181                 for (n = t->deps; n != NULL; n = n->next)
7182                     {
7183                       if (n->version_needed == NULL)
7184                         {
7185                           /* This can happen if there was an error in the
7186                                version script.  */
7187                           defaux.vda_name = 0;
7188                         }
7189                       else
7190                         {
7191                           defaux.vda_name = n->version_needed->name_indx;
7192                           _bfd_elf_strtab_addref (elf_hash_table (info)->dynstr,
7193                                                         defaux.vda_name);
7194                         }
7195                       if (n->next == NULL)
7196                         defaux.vda_next = 0;
7197                       else
7198                         defaux.vda_next = sizeof (Elf_External_Verdaux);
7199 
7200                       _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
7201                                                        (Elf_External_Verdaux *) p);
7202                       p += sizeof (Elf_External_Verdaux);
7203                     }
7204               }
7205 
7206             elf_tdata (output_bfd)->cverdefs = cdefs;
7207           }
7208     }
7209 
7210   if (info->gc_sections && bed->can_gc_sections)
7211     {
7212       struct elf_gc_sweep_symbol_info sweep_info;
7213 
7214       /* Remove the symbols that were in the swept sections from the
7215            dynamic symbol table.  */
7216       sweep_info.info = info;
7217       sweep_info.hide_symbol = bed->elf_backend_hide_symbol;
7218       elf_link_hash_traverse (elf_hash_table (info), elf_gc_sweep_symbol,
7219                                     &sweep_info);
7220     }
7221 
7222   if (dynobj != NULL && elf_hash_table (info)->dynamic_sections_created)
7223     {
7224       asection *s;
7225       struct elf_find_verdep_info sinfo;
7226 
7227       /* Work out the size of the version reference section.  */
7228 
7229       s = bfd_get_linker_section (dynobj, ".gnu.version_r");
7230       BFD_ASSERT (s != NULL);
7231 
7232       sinfo.info = info;
7233       sinfo.vers = elf_tdata (output_bfd)->cverdefs;
7234       if (sinfo.vers == 0)
7235           sinfo.vers = 1;
7236       sinfo.failed = false;
7237 
7238       elf_link_hash_traverse (elf_hash_table (info),
7239                                     _bfd_elf_link_find_version_dependencies,
7240                                     &sinfo);
7241       if (sinfo.failed)
7242           return false;
7243 
7244       bed->elf_backend_add_glibc_version_dependency (&sinfo);
7245       if (sinfo.failed)
7246           return false;
7247 
7248       if (elf_tdata (output_bfd)->verref == NULL)
7249           s->flags |= SEC_EXCLUDE;
7250       else
7251           {
7252             Elf_Internal_Verneed *vn;
7253             unsigned int size;
7254             unsigned int crefs;
7255             bfd_byte *p;
7256 
7257             /* Build the version dependency section.  */
7258             size = 0;
7259             crefs = 0;
7260             for (vn = elf_tdata (output_bfd)->verref;
7261                  vn != NULL;
7262                  vn = vn->vn_nextref)
7263               {
7264                 Elf_Internal_Vernaux *a;
7265 
7266                 size += sizeof (Elf_External_Verneed);
7267                 ++crefs;
7268                 for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
7269                     size += sizeof (Elf_External_Vernaux);
7270               }
7271 
7272             s->size = size;
7273             s->contents = (unsigned char *) bfd_alloc (output_bfd, s->size);
7274             if (s->contents == NULL)
7275               return false;
7276 
7277             p = s->contents;
7278             for (vn = elf_tdata (output_bfd)->verref;
7279                  vn != NULL;
7280                  vn = vn->vn_nextref)
7281               {
7282                 unsigned int caux;
7283                 Elf_Internal_Vernaux *a;
7284                 size_t indx;
7285 
7286                 caux = 0;
7287                 for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
7288                     ++caux;
7289 
7290                 vn->vn_version = VER_NEED_CURRENT;
7291                 vn->vn_cnt = caux;
7292                 indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
7293                                                     elf_dt_name (vn->vn_bfd) != NULL
7294                                                     ? elf_dt_name (vn->vn_bfd)
7295                                                     : lbasename (bfd_get_filename
7296                                                                    (vn->vn_bfd)),
7297                                                     false);
7298                 if (indx == (size_t) -1)
7299                     return false;
7300                 vn->vn_file = indx;
7301                 vn->vn_aux = sizeof (Elf_External_Verneed);
7302                 if (vn->vn_nextref == NULL)
7303                     vn->vn_next = 0;
7304                 else
7305                     vn->vn_next = (sizeof (Elf_External_Verneed)
7306                                      + caux * sizeof (Elf_External_Vernaux));
7307 
7308                 _bfd_elf_swap_verneed_out (output_bfd, vn,
7309                                                    (Elf_External_Verneed *) p);
7310                 p += sizeof (Elf_External_Verneed);
7311 
7312                 for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
7313                     {
7314                       a->vna_hash = bfd_elf_hash (a->vna_nodename);
7315                       indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
7316                                                         a->vna_nodename, false);
7317                       if (indx == (size_t) -1)
7318                         return false;
7319                       a->vna_name = indx;
7320                       if (a->vna_nextptr == NULL)
7321                         a->vna_next = 0;
7322                       else
7323                         a->vna_next = sizeof (Elf_External_Vernaux);
7324 
7325                       _bfd_elf_swap_vernaux_out (output_bfd, a,
7326                                                        (Elf_External_Vernaux *) p);
7327                       p += sizeof (Elf_External_Vernaux);
7328                     }
7329               }
7330 
7331             elf_tdata (output_bfd)->cverrefs = crefs;
7332           }
7333     }
7334 
7335   if (bfd_link_relocatable (info)
7336       && !_bfd_elf_size_group_sections (info))
7337     return false;
7338 
7339   /* Determine any GNU_STACK segment requirements, after the backend
7340      has had a chance to set a default segment size.  */
7341   if (info->execstack)
7342     {
7343       /* If the user has explicitly requested warnings, then generate one even
7344            though the choice is the result of another command line option.  */
7345       if (info->warn_execstack == 1)
7346           {
7347             if (info->error_execstack)
7348               {
7349                 _bfd_error_handler
7350                     (_("\
7351 error: creating an executable stack because of -z execstack command line option"));
7352                 return false;
7353               }
7354 
7355             _bfd_error_handler
7356               (_("\
7357 warning: enabling an executable stack because of -z execstack command line option"));
7358           }
7359 
7360       elf_stack_flags (output_bfd) = PF_R | PF_W | PF_X;
7361     }
7362   else if (info->noexecstack)
7363     elf_stack_flags (output_bfd) = PF_R | PF_W;
7364   else
7365     {
7366       bfd *inputobj;
7367       asection *notesec = NULL;
7368       bfd *noteobj = NULL;
7369       bfd *emptyobj = NULL;
7370       int exec = 0;
7371 
7372       for (inputobj = info->input_bfds;
7373              inputobj;
7374              inputobj = inputobj->link.next)
7375           {
7376             asection *s;
7377 
7378             if (inputobj->flags
7379                 & (DYNAMIC | EXEC_P | BFD_PLUGIN | BFD_LINKER_CREATED))
7380               continue;
7381             s = inputobj->sections;
7382             if (s == NULL || s->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
7383               continue;
7384 
7385             s = bfd_get_section_by_name (inputobj, ".note.GNU-stack");
7386             if (s)
7387               {
7388                 notesec = s;
7389                 if (s->flags & SEC_CODE)
7390                     {
7391                       noteobj = inputobj;
7392                       exec = PF_X;
7393                       /* There is no point in scanning the remaining bfds.  */
7394                       break;
7395                     }
7396               }
7397             else if (bed->default_execstack && info->default_execstack)
7398               {
7399                 exec = PF_X;
7400                 emptyobj = inputobj;
7401               }
7402           }
7403 
7404       if (notesec || info->stacksize > 0)
7405           {
7406             if (exec)
7407               {
7408                 if (info->warn_execstack != 0)
7409                     {
7410                       /* PR 29072: Because an executable stack is a serious
7411                          security risk, make sure that the user knows that it is
7412                          being enabled despite the fact that it was not requested
7413                          on the command line.  */
7414                       if (noteobj)
7415                         {
7416                           if (info->error_execstack)
7417                               {
7418                                 _bfd_error_handler (_("\
7419 error: %s: is triggering the generation of an executable stack (because it has an executable .note.GNU-stack section)"),
7420                                                         bfd_get_filename (noteobj));
7421                                 return false;
7422                               }
7423 
7424                           _bfd_error_handler (_("\
7425 warning: %s: requires executable stack (because the .note.GNU-stack section is executable)"),
7426                            bfd_get_filename (noteobj));
7427                         }
7428                       else if (emptyobj)
7429                         {
7430                           if (info->error_execstack)
7431                               {
7432                                 _bfd_error_handler (_("\
7433 error: %s: is triggering the generation of an executable stack because it does not have a .note.GNU-stack section"),
7434                                                         bfd_get_filename (emptyobj));
7435                                 return false;
7436                               }
7437 
7438                           _bfd_error_handler (_("\
7439 warning: %s: missing .note.GNU-stack section implies executable stack"),
7440                                                     bfd_get_filename (emptyobj));
7441                           _bfd_error_handler (_("\
7442 NOTE: This behaviour is deprecated and will be removed in a future version of the linker"));
7443                         }
7444                     }
7445               }
7446             elf_stack_flags (output_bfd) = PF_R | PF_W | exec;
7447           }
7448 
7449       if (notesec && exec && bfd_link_relocatable (info)
7450             && notesec->output_section != bfd_abs_section_ptr)
7451           notesec->output_section->flags |= SEC_CODE;
7452     }
7453 
7454   if (dynobj != NULL && elf_hash_table (info)->dynamic_sections_created)
7455     {
7456       struct elf_info_failed eif;
7457       struct elf_link_hash_entry *h;
7458       asection *dynstr;
7459       asection *s;
7460 
7461       *sinterpptr = bfd_get_linker_section (dynobj, ".interp");
7462       BFD_ASSERT (*sinterpptr != NULL || !bfd_link_executable (info) || info->nointerp);
7463 
7464       if (info->symbolic)
7465           {
7466             if (!_bfd_elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
7467               return false;
7468             info->flags |= DF_SYMBOLIC;
7469           }
7470 
7471       if (rpath != NULL)
7472           {
7473             size_t indx;
7474             bfd_vma tag;
7475 
7476             indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr, rpath,
7477                                               true);
7478             if (indx == (size_t) -1)
7479               return false;
7480 
7481             tag = info->new_dtags ? DT_RUNPATH : DT_RPATH;
7482             if (!_bfd_elf_add_dynamic_entry (info, tag, indx))
7483               return false;
7484           }
7485 
7486       if (filter_shlib != NULL)
7487           {
7488             size_t indx;
7489 
7490             indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
7491                                               filter_shlib, true);
7492             if (indx == (size_t) -1
7493                 || !_bfd_elf_add_dynamic_entry (info, DT_FILTER, indx))
7494               return false;
7495           }
7496 
7497       if (auxiliary_filters != NULL)
7498           {
7499             const char * const *p;
7500 
7501             for (p = auxiliary_filters; *p != NULL; p++)
7502               {
7503                 size_t indx;
7504 
7505                 indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
7506                                                     *p, true);
7507                 if (indx == (size_t) -1
7508                       || !_bfd_elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
7509                     return false;
7510               }
7511           }
7512 
7513       if (audit != NULL)
7514           {
7515             size_t indx;
7516 
7517             indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr, audit,
7518                                               true);
7519             if (indx == (size_t) -1
7520                 || !_bfd_elf_add_dynamic_entry (info, DT_AUDIT, indx))
7521               return false;
7522           }
7523 
7524       if (depaudit != NULL)
7525           {
7526             size_t indx;
7527 
7528             indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr, depaudit,
7529                                               true);
7530             if (indx == (size_t) -1
7531                 || !_bfd_elf_add_dynamic_entry (info, DT_DEPAUDIT, indx))
7532               return false;
7533           }
7534 
7535       eif.info = info;
7536       eif.failed = false;
7537 
7538       /* Find all symbols which were defined in a dynamic object and make
7539            the backend pick a reasonable value for them.  */
7540       elf_link_hash_traverse (elf_hash_table (info),
7541                                     _bfd_elf_adjust_dynamic_symbol,
7542                                     &eif);
7543       if (eif.failed)
7544           return false;
7545 
7546       /* Add some entries to the .dynamic section.  We fill in some of the
7547            values later, in bfd_elf_final_link, but we must add the entries
7548            now so that we know the final size of the .dynamic section.  */
7549 
7550       /* If there are initialization and/or finalization functions to
7551            call then add the corresponding DT_INIT/DT_FINI entries.  */
7552       h = (info->init_function
7553              ? elf_link_hash_lookup (elf_hash_table (info),
7554                                            info->init_function, false,
7555                                            false, false)
7556              : NULL);
7557       if (h != NULL
7558             && (h->ref_regular
7559                 || h->def_regular))
7560           {
7561             if (!_bfd_elf_add_dynamic_entry (info, DT_INIT, 0))
7562               return false;
7563           }
7564       h = (info->fini_function
7565              ? elf_link_hash_lookup (elf_hash_table (info),
7566                                            info->fini_function, false,
7567                                            false, false)
7568              : NULL);
7569       if (h != NULL
7570             && (h->ref_regular
7571                 || h->def_regular))
7572           {
7573             if (!_bfd_elf_add_dynamic_entry (info, DT_FINI, 0))
7574               return false;
7575           }
7576 
7577       s = bfd_get_section_by_name (output_bfd, ".preinit_array");
7578       if (s != NULL && s->linker_has_input)
7579           {
7580             /* DT_PREINIT_ARRAY is not allowed in shared library.  */
7581             if (! bfd_link_executable (info))
7582               {
7583                 bfd *sub;
7584                 asection *o;
7585 
7586                 for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
7587                     if (bfd_get_flavour (sub) == bfd_target_elf_flavour
7588                         && (o = sub->sections) != NULL
7589                         && o->sec_info_type != SEC_INFO_TYPE_JUST_SYMS)
7590                       for (o = sub->sections; o != NULL; o = o->next)
7591                         if (elf_section_data (o)->this_hdr.sh_type
7592                               == SHT_PREINIT_ARRAY)
7593                           {
7594                               _bfd_error_handler
7595                                 (_("%pB: .preinit_array section is not allowed in DSO"),
7596                                  sub);
7597                               break;
7598                           }
7599 
7600                 bfd_set_error (bfd_error_nonrepresentable_section);
7601                 return false;
7602               }
7603 
7604             if (!_bfd_elf_add_dynamic_entry (info, DT_PREINIT_ARRAY, 0)
7605                 || !_bfd_elf_add_dynamic_entry (info, DT_PREINIT_ARRAYSZ, 0))
7606               return false;
7607           }
7608       s = bfd_get_section_by_name (output_bfd, ".init_array");
7609       if (s != NULL && s->linker_has_input)
7610           {
7611             if (!_bfd_elf_add_dynamic_entry (info, DT_INIT_ARRAY, 0)
7612                 || !_bfd_elf_add_dynamic_entry (info, DT_INIT_ARRAYSZ, 0))
7613               return false;
7614           }
7615       s = bfd_get_section_by_name (output_bfd, ".fini_array");
7616       if (s != NULL && s->linker_has_input)
7617           {
7618             if (!_bfd_elf_add_dynamic_entry (info, DT_FINI_ARRAY, 0)
7619                 || !_bfd_elf_add_dynamic_entry (info, DT_FINI_ARRAYSZ, 0))
7620               return false;
7621           }
7622 
7623       dynstr = bfd_get_linker_section (dynobj, ".dynstr");
7624       /* If .dynstr is excluded from the link, we don't want any of
7625            these tags.  Strictly, we should be checking each section
7626            individually;  This quick check covers for the case where
7627            someone does a /DISCARD/ : { *(*) }.  */
7628       if (dynstr != NULL && dynstr->output_section != bfd_abs_section_ptr)
7629           {
7630             bfd_size_type strsize;
7631 
7632             strsize = _bfd_elf_strtab_size (elf_hash_table (info)->dynstr);
7633             if ((info->emit_hash
7634                  && !_bfd_elf_add_dynamic_entry (info, DT_HASH, 0))
7635                 || (info->emit_gnu_hash
7636                       && (bed->record_xhash_symbol == NULL
7637                           && !_bfd_elf_add_dynamic_entry (info, DT_GNU_HASH, 0)))
7638                 || !_bfd_elf_add_dynamic_entry (info, DT_STRTAB, 0)
7639                 || !_bfd_elf_add_dynamic_entry (info, DT_SYMTAB, 0)
7640                 || !_bfd_elf_add_dynamic_entry (info, DT_STRSZ, strsize)
7641                 || !_bfd_elf_add_dynamic_entry (info, DT_SYMENT,
7642                                                         bed->s->sizeof_sym)
7643                 || (info->gnu_flags_1
7644                       && !_bfd_elf_add_dynamic_entry (info, DT_GNU_FLAGS_1,
7645                                                               info->gnu_flags_1)))
7646               return false;
7647           }
7648     }
7649 
7650   if (! _bfd_elf_maybe_strip_eh_frame_hdr (info))
7651     return false;
7652 
7653   /* The backend must work out the sizes of all the other dynamic
7654      sections.  */
7655   if (bed->elf_backend_late_size_sections != NULL
7656       && !bed->elf_backend_late_size_sections (output_bfd, info))
7657     return false;
7658 
7659   if (dynobj != NULL && elf_hash_table (info)->dynamic_sections_created)
7660     {
7661       if (elf_tdata (output_bfd)->cverdefs)
7662           {
7663             unsigned int crefs = elf_tdata (output_bfd)->cverdefs;
7664 
7665             if (!_bfd_elf_add_dynamic_entry (info, DT_VERDEF, 0)
7666                 || !_bfd_elf_add_dynamic_entry (info, DT_VERDEFNUM, crefs))
7667               return false;
7668           }
7669 
7670       if ((info->new_dtags && info->flags) || (info->flags & DF_STATIC_TLS))
7671           {
7672             if (!_bfd_elf_add_dynamic_entry (info, DT_FLAGS, info->flags))
7673               return false;
7674           }
7675       else if (info->flags & DF_BIND_NOW)
7676           {
7677             if (!_bfd_elf_add_dynamic_entry (info, DT_BIND_NOW, 0))
7678               return false;
7679           }
7680 
7681       if (info->flags_1)
7682           {
7683             if (bfd_link_executable (info))
7684               info->flags_1 &= ~ (DF_1_INITFIRST
7685                                         | DF_1_NODELETE
7686                                         | DF_1_NOOPEN);
7687             if (!_bfd_elf_add_dynamic_entry (info, DT_FLAGS_1, info->flags_1))
7688               return false;
7689           }
7690 
7691       if (elf_tdata (output_bfd)->cverrefs)
7692           {
7693             unsigned int crefs = elf_tdata (output_bfd)->cverrefs;
7694 
7695             if (!_bfd_elf_add_dynamic_entry (info, DT_VERNEED, 0)
7696                 || !_bfd_elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
7697               return false;
7698           }
7699 
7700       if ((elf_tdata (output_bfd)->cverrefs == 0
7701              && elf_tdata (output_bfd)->cverdefs == 0)
7702             || _bfd_elf_link_renumber_dynsyms (output_bfd, info, NULL) <= 1)
7703           {
7704             asection *s;
7705 
7706             s = bfd_get_linker_section (dynobj, ".gnu.version");
7707             s->flags |= SEC_EXCLUDE;
7708           }
7709     }
7710   return true;
7711 }
7712 
7713 /* Find the first non-excluded output section.  We'll use its
7714    section symbol for some emitted relocs.  */
7715 void
_bfd_elf_init_1_index_section(bfd * output_bfd,struct bfd_link_info * info)7716 _bfd_elf_init_1_index_section (bfd *output_bfd, struct bfd_link_info *info)
7717 {
7718   asection *s;
7719   asection *found = NULL;
7720 
7721   for (s = output_bfd->sections; s != NULL; s = s->next)
7722     if ((s->flags & (SEC_EXCLUDE | SEC_ALLOC)) == SEC_ALLOC
7723           && !_bfd_elf_omit_section_dynsym_default (output_bfd, info, s))
7724       {
7725           found = s;
7726           if ((s->flags & SEC_THREAD_LOCAL) == 0)
7727             break;
7728       }
7729   elf_hash_table (info)->text_index_section = found;
7730 }
7731 
7732 /* Find two non-excluded output sections, one for code, one for data.
7733    We'll use their section symbols for some emitted relocs.  */
7734 void
_bfd_elf_init_2_index_sections(bfd * output_bfd,struct bfd_link_info * info)7735 _bfd_elf_init_2_index_sections (bfd *output_bfd, struct bfd_link_info *info)
7736 {
7737   asection *s;
7738   asection *found = NULL;
7739 
7740   /* Data first, since setting text_index_section changes
7741      _bfd_elf_omit_section_dynsym_default.  */
7742   for (s = output_bfd->sections; s != NULL; s = s->next)
7743     if ((s->flags & (SEC_EXCLUDE | SEC_ALLOC)) == SEC_ALLOC
7744           && !(s->flags & SEC_READONLY)
7745           && !_bfd_elf_omit_section_dynsym_default (output_bfd, info, s))
7746       {
7747           found = s;
7748           if ((s->flags & SEC_THREAD_LOCAL) == 0)
7749             break;
7750       }
7751   elf_hash_table (info)->data_index_section = found;
7752 
7753   for (s = output_bfd->sections; s != NULL; s = s->next)
7754     if ((s->flags & (SEC_EXCLUDE | SEC_ALLOC)) == SEC_ALLOC
7755           && (s->flags & SEC_READONLY)
7756           && !_bfd_elf_omit_section_dynsym_default (output_bfd, info, s))
7757       {
7758           found = s;
7759           break;
7760       }
7761   elf_hash_table (info)->text_index_section = found;
7762 }
7763 
7764 #define GNU_HASH_SECTION_NAME(bed)                              \
7765   (bed)->record_xhash_symbol != NULL ? ".MIPS.xhash" : ".gnu.hash"
7766 
7767 bool
bfd_elf_size_dynsym_hash_dynstr(bfd * output_bfd,struct bfd_link_info * info)7768 bfd_elf_size_dynsym_hash_dynstr (bfd *output_bfd, struct bfd_link_info *info)
7769 {
7770   const struct elf_backend_data *bed;
7771   unsigned long section_sym_count;
7772   bfd_size_type dynsymcount = 0;
7773 
7774   if (!is_elf_hash_table (info->hash))
7775     return true;
7776 
7777   bed = get_elf_backend_data (output_bfd);
7778   (*bed->elf_backend_init_index_section) (output_bfd, info);
7779 
7780   /* Assign dynsym indices.  In a shared library we generate a section
7781      symbol for each output section, which come first.  Next come all
7782      of the back-end allocated local dynamic syms, followed by the rest
7783      of the global symbols.
7784 
7785      This is usually not needed for static binaries, however backends
7786      can request to always do it, e.g. the MIPS backend uses dynamic
7787      symbol counts to lay out GOT, which will be produced in the
7788      presence of GOT relocations even in static binaries (holding fixed
7789      data in that case, to satisfy those relocations).  */
7790 
7791   if (elf_hash_table (info)->dynamic_sections_created
7792       || bed->always_renumber_dynsyms)
7793     dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info,
7794                                                               &section_sym_count);
7795 
7796   if (elf_hash_table (info)->dynamic_sections_created)
7797     {
7798       bfd *dynobj;
7799       asection *s;
7800       unsigned int dtagcount;
7801 
7802       dynobj = elf_hash_table (info)->dynobj;
7803 
7804       /* Work out the size of the symbol version section.  */
7805       s = bfd_get_linker_section (dynobj, ".gnu.version");
7806       BFD_ASSERT (s != NULL);
7807       if ((s->flags & SEC_EXCLUDE) == 0)
7808           {
7809             s->size = dynsymcount * sizeof (Elf_External_Versym);
7810             s->contents = (unsigned char *) bfd_zalloc (output_bfd, s->size);
7811             if (s->contents == NULL)
7812               return false;
7813 
7814             if (!_bfd_elf_add_dynamic_entry (info, DT_VERSYM, 0))
7815               return false;
7816           }
7817 
7818       /* Set the size of the .dynsym and .hash sections.  We counted
7819            the number of dynamic symbols in elf_link_add_object_symbols.
7820            We will build the contents of .dynsym and .hash when we build
7821            the final symbol table, because until then we do not know the
7822            correct value to give the symbols.  We built the .dynstr
7823            section as we went along in elf_link_add_object_symbols.  */
7824       s = elf_hash_table (info)->dynsym;
7825       BFD_ASSERT (s != NULL);
7826       s->size = dynsymcount * bed->s->sizeof_sym;
7827 
7828       s->contents = (unsigned char *) bfd_alloc (output_bfd, s->size);
7829       if (s->contents == NULL)
7830           return false;
7831 
7832       /* The first entry in .dynsym is a dummy symbol.  Clear all the
7833            section syms, in case we don't output them all.  */
7834       ++section_sym_count;
7835       memset (s->contents, 0, section_sym_count * bed->s->sizeof_sym);
7836 
7837       elf_hash_table (info)->bucketcount = 0;
7838 
7839       /* Compute the size of the hashing table.  As a side effect this
7840            computes the hash values for all the names we export.  */
7841       if (info->emit_hash)
7842           {
7843             unsigned long int *hashcodes;
7844             struct hash_codes_info hashinf;
7845             bfd_size_type amt;
7846             unsigned long int nsyms;
7847             size_t bucketcount;
7848             size_t hash_entry_size;
7849 
7850             /* Compute the hash values for all exported symbols.  At the same
7851                time store the values in an array so that we could use them for
7852                optimizations.  */
7853             amt = dynsymcount * sizeof (unsigned long int);
7854             hashcodes = (unsigned long int *) bfd_malloc (amt);
7855             if (hashcodes == NULL)
7856               return false;
7857             hashinf.hashcodes = hashcodes;
7858             hashinf.error = false;
7859 
7860             /* Put all hash values in HASHCODES.  */
7861             elf_link_hash_traverse (elf_hash_table (info),
7862                                           elf_collect_hash_codes, &hashinf);
7863             if (hashinf.error)
7864               {
7865                 free (hashcodes);
7866                 return false;
7867               }
7868 
7869             nsyms = hashinf.hashcodes - hashcodes;
7870             bucketcount
7871               = compute_bucket_count (info, hashcodes, nsyms, 0);
7872             free (hashcodes);
7873 
7874             if (bucketcount == 0 && nsyms > 0)
7875               return false;
7876 
7877             elf_hash_table (info)->bucketcount = bucketcount;
7878 
7879             s = bfd_get_linker_section (dynobj, ".hash");
7880             BFD_ASSERT (s != NULL);
7881             hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
7882             s->size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
7883             s->contents = (unsigned char *) bfd_zalloc (output_bfd, s->size);
7884             if (s->contents == NULL)
7885               return false;
7886 
7887             bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
7888             bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
7889                        s->contents + hash_entry_size);
7890           }
7891 
7892       if (info->emit_gnu_hash)
7893           {
7894             size_t i, cnt;
7895             unsigned char *contents;
7896             struct collect_gnu_hash_codes cinfo;
7897             bfd_size_type amt;
7898             size_t bucketcount;
7899 
7900             memset (&cinfo, 0, sizeof (cinfo));
7901 
7902             /* Compute the hash values for all exported symbols.  At the same
7903                time store the values in an array so that we could use them for
7904                optimizations.  */
7905             amt = dynsymcount * 2 * sizeof (unsigned long int);
7906             cinfo.hashcodes = (long unsigned int *) bfd_malloc (amt);
7907             if (cinfo.hashcodes == NULL)
7908               return false;
7909 
7910             cinfo.hashval = cinfo.hashcodes + dynsymcount;
7911             cinfo.min_dynindx = -1;
7912             cinfo.output_bfd = output_bfd;
7913             cinfo.bed = bed;
7914 
7915             /* Put all hash values in HASHCODES.  */
7916             elf_link_hash_traverse (elf_hash_table (info),
7917                                           elf_collect_gnu_hash_codes, &cinfo);
7918             if (cinfo.error)
7919               {
7920                 free (cinfo.hashcodes);
7921                 return false;
7922               }
7923 
7924             bucketcount
7925               = compute_bucket_count (info, cinfo.hashcodes, cinfo.nsyms, 1);
7926 
7927             if (bucketcount == 0)
7928               {
7929                 free (cinfo.hashcodes);
7930                 return false;
7931               }
7932 
7933             s = bfd_get_linker_section (dynobj, GNU_HASH_SECTION_NAME (bed));
7934             BFD_ASSERT (s != NULL);
7935 
7936             if (cinfo.nsyms == 0)
7937               {
7938                 /* Empty .gnu.hash or .MIPS.xhash section is special.  */
7939                 BFD_ASSERT (cinfo.min_dynindx == -1);
7940                 free (cinfo.hashcodes);
7941                 s->size = 5 * 4 + bed->s->arch_size / 8;
7942                 contents = (unsigned char *) bfd_zalloc (output_bfd, s->size);
7943                 if (contents == NULL)
7944                     return false;
7945                 s->contents = contents;
7946                 /* 1 empty bucket.  */
7947                 bfd_put_32 (output_bfd, 1, contents);
7948                 /* SYMIDX above the special symbol 0.  */
7949                 bfd_put_32 (output_bfd, 1, contents + 4);
7950                 /* Just one word for bitmask.  */
7951                 bfd_put_32 (output_bfd, 1, contents + 8);
7952                 /* Only hash fn bloom filter.  */
7953                 bfd_put_32 (output_bfd, 0, contents + 12);
7954                 /* No hashes are valid - empty bitmask.  */
7955                 bfd_put (bed->s->arch_size, output_bfd, 0, contents + 16);
7956                 /* No hashes in the only bucket.  */
7957                 bfd_put_32 (output_bfd, 0,
7958                                 contents + 16 + bed->s->arch_size / 8);
7959               }
7960             else
7961               {
7962                 unsigned long int maskwords, maskbitslog2, x;
7963                 BFD_ASSERT (cinfo.min_dynindx != -1);
7964 
7965                 x = cinfo.nsyms;
7966                 maskbitslog2 = 1;
7967                 while ((x >>= 1) != 0)
7968                     ++maskbitslog2;
7969                 if (maskbitslog2 < 3)
7970                     maskbitslog2 = 5;
7971                 else if ((1 << (maskbitslog2 - 2)) & cinfo.nsyms)
7972                     maskbitslog2 = maskbitslog2 + 3;
7973                 else
7974                     maskbitslog2 = maskbitslog2 + 2;
7975                 if (bed->s->arch_size == 64)
7976                     {
7977                       if (maskbitslog2 == 5)
7978                         maskbitslog2 = 6;
7979                       cinfo.shift1 = 6;
7980                     }
7981                 else
7982                     cinfo.shift1 = 5;
7983                 cinfo.mask = (1 << cinfo.shift1) - 1;
7984                 cinfo.shift2 = maskbitslog2;
7985                 cinfo.maskbits = 1 << maskbitslog2;
7986                 maskwords = 1 << (maskbitslog2 - cinfo.shift1);
7987                 amt = bucketcount * sizeof (unsigned long int) * 2;
7988                 amt += maskwords * sizeof (bfd_vma);
7989                 cinfo.bitmask = (bfd_vma *) bfd_malloc (amt);
7990                 if (cinfo.bitmask == NULL)
7991                     {
7992                       free (cinfo.hashcodes);
7993                       return false;
7994                     }
7995 
7996                 cinfo.counts = (long unsigned int *) (cinfo.bitmask + maskwords);
7997                 cinfo.indx = cinfo.counts + bucketcount;
7998                 cinfo.symindx = dynsymcount - cinfo.nsyms;
7999                 memset (cinfo.bitmask, 0, maskwords * sizeof (bfd_vma));
8000 
8001                 /* Determine how often each hash bucket is used.  */
8002                 memset (cinfo.counts, 0, bucketcount * sizeof (cinfo.counts[0]));
8003                 for (i = 0; i < cinfo.nsyms; ++i)
8004                     ++cinfo.counts[cinfo.hashcodes[i] % bucketcount];
8005 
8006                 for (i = 0, cnt = cinfo.symindx; i < bucketcount; ++i)
8007                     if (cinfo.counts[i] != 0)
8008                       {
8009                         cinfo.indx[i] = cnt;
8010                         cnt += cinfo.counts[i];
8011                       }
8012                 BFD_ASSERT (cnt == dynsymcount);
8013                 cinfo.bucketcount = bucketcount;
8014                 cinfo.local_indx = cinfo.min_dynindx;
8015 
8016                 s->size = (4 + bucketcount + cinfo.nsyms) * 4;
8017                 s->size += cinfo.maskbits / 8;
8018                 if (bed->record_xhash_symbol != NULL)
8019                     s->size += cinfo.nsyms * 4;
8020                 contents = (unsigned char *) bfd_zalloc (output_bfd, s->size);
8021                 if (contents == NULL)
8022                     {
8023                       free (cinfo.bitmask);
8024                       free (cinfo.hashcodes);
8025                       return false;
8026                     }
8027 
8028                 s->contents = contents;
8029                 bfd_put_32 (output_bfd, bucketcount, contents);
8030                 bfd_put_32 (output_bfd, cinfo.symindx, contents + 4);
8031                 bfd_put_32 (output_bfd, maskwords, contents + 8);
8032                 bfd_put_32 (output_bfd, cinfo.shift2, contents + 12);
8033                 contents += 16 + cinfo.maskbits / 8;
8034 
8035                 for (i = 0; i < bucketcount; ++i)
8036                     {
8037                       if (cinfo.counts[i] == 0)
8038                         bfd_put_32 (output_bfd, 0, contents);
8039                       else
8040                         bfd_put_32 (output_bfd, cinfo.indx[i], contents);
8041                       contents += 4;
8042                     }
8043 
8044                 cinfo.contents = contents;
8045 
8046                 cinfo.xlat = contents + cinfo.nsyms * 4 - s->contents;
8047                 /* Renumber dynamic symbols, if populating .gnu.hash section.
8048                      If using .MIPS.xhash, populate the translation table.  */
8049                 elf_link_hash_traverse (elf_hash_table (info),
8050                                               elf_gnu_hash_process_symidx, &cinfo);
8051 
8052                 contents = s->contents + 16;
8053                 for (i = 0; i < maskwords; ++i)
8054                     {
8055                       bfd_put (bed->s->arch_size, output_bfd, cinfo.bitmask[i],
8056                                  contents);
8057                       contents += bed->s->arch_size / 8;
8058                     }
8059 
8060                 free (cinfo.bitmask);
8061                 free (cinfo.hashcodes);
8062               }
8063           }
8064 
8065       s = bfd_get_linker_section (dynobj, ".dynstr");
8066       BFD_ASSERT (s != NULL);
8067 
8068       elf_finalize_dynstr (output_bfd, info);
8069 
8070       s->size = _bfd_elf_strtab_size (elf_hash_table (info)->dynstr);
8071 
8072       for (dtagcount = 0; dtagcount <= info->spare_dynamic_tags; ++dtagcount)
8073           if (!_bfd_elf_add_dynamic_entry (info, DT_NULL, 0))
8074             return false;
8075     }
8076 
8077   return true;
8078 }
8079 
8080 /* Make sure sec_info_type is cleared if sec_info is cleared too.  */
8081 
8082 static void
merge_sections_remove_hook(bfd * abfd ATTRIBUTE_UNUSED,asection * sec)8083 merge_sections_remove_hook (bfd *abfd ATTRIBUTE_UNUSED,
8084                                   asection *sec)
8085 {
8086   BFD_ASSERT (sec->sec_info_type == SEC_INFO_TYPE_MERGE);
8087   sec->sec_info_type = SEC_INFO_TYPE_NONE;
8088 }
8089 
8090 /* Finish SHF_MERGE section merging.  */
8091 
8092 bool
_bfd_elf_merge_sections(bfd * obfd,struct bfd_link_info * info)8093 _bfd_elf_merge_sections (bfd *obfd, struct bfd_link_info *info)
8094 {
8095   bfd *ibfd;
8096   asection *sec;
8097 
8098   if (!is_elf_hash_table (info->hash))
8099     return false;
8100 
8101   for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
8102     if ((ibfd->flags & DYNAMIC) == 0
8103           && bfd_get_flavour (ibfd) == bfd_target_elf_flavour
8104           && (elf_elfheader (ibfd)->e_ident[EI_CLASS]
8105               == get_elf_backend_data (obfd)->s->elfclass))
8106       for (sec = ibfd->sections; sec != NULL; sec = sec->next)
8107           if ((sec->flags & SEC_MERGE) != 0
8108               && !bfd_is_abs_section (sec->output_section))
8109             {
8110               struct bfd_elf_section_data *secdata;
8111 
8112               secdata = elf_section_data (sec);
8113               if (! _bfd_add_merge_section (obfd,
8114                                                     &elf_hash_table (info)->merge_info,
8115                                                     sec, &secdata->sec_info))
8116                 return false;
8117               else if (secdata->sec_info)
8118                 sec->sec_info_type = SEC_INFO_TYPE_MERGE;
8119             }
8120 
8121   if (elf_hash_table (info)->merge_info != NULL)
8122     _bfd_merge_sections (obfd, info, elf_hash_table (info)->merge_info,
8123                                merge_sections_remove_hook);
8124   return true;
8125 }
8126 
8127 /* Create an entry in an ELF linker hash table.  */
8128 
8129 struct bfd_hash_entry *
_bfd_elf_link_hash_newfunc(struct bfd_hash_entry * entry,struct bfd_hash_table * table,const char * string)8130 _bfd_elf_link_hash_newfunc (struct bfd_hash_entry *entry,
8131                                   struct bfd_hash_table *table,
8132                                   const char *string)
8133 {
8134   /* Allocate the structure if it has not already been allocated by a
8135      subclass.  */
8136   if (entry == NULL)
8137     {
8138       entry = (struct bfd_hash_entry *)
8139           bfd_hash_allocate (table, sizeof (struct elf_link_hash_entry));
8140       if (entry == NULL)
8141           return entry;
8142     }
8143 
8144   /* Call the allocation method of the superclass.  */
8145   entry = _bfd_link_hash_newfunc (entry, table, string);
8146   if (entry != NULL)
8147     {
8148       struct elf_link_hash_entry *ret = (struct elf_link_hash_entry *) entry;
8149       struct elf_link_hash_table *htab = (struct elf_link_hash_table *) table;
8150 
8151       /* Set local fields.  */
8152       ret->indx = -1;
8153       ret->dynindx = -1;
8154       ret->got = htab->init_got_refcount;
8155       ret->plt = htab->init_plt_refcount;
8156       memset (&ret->size, 0, (sizeof (struct elf_link_hash_entry)
8157                                     - offsetof (struct elf_link_hash_entry, size)));
8158       /* Assume that we have been called by a non-ELF symbol reader.
8159            This flag is then reset by the code which reads an ELF input
8160            file.  This ensures that a symbol created by a non-ELF symbol
8161            reader will have the flag set correctly.  */
8162       ret->non_elf = 1;
8163     }
8164 
8165   return entry;
8166 }
8167 
8168 /* Copy data from an indirect symbol to its direct symbol, hiding the
8169    old indirect symbol.  Also used for copying flags to a weakdef.  */
8170 
8171 void
_bfd_elf_link_hash_copy_indirect(struct bfd_link_info * info,struct elf_link_hash_entry * dir,struct elf_link_hash_entry * ind)8172 _bfd_elf_link_hash_copy_indirect (struct bfd_link_info *info,
8173                                           struct elf_link_hash_entry *dir,
8174                                           struct elf_link_hash_entry *ind)
8175 {
8176   struct elf_link_hash_table *htab;
8177 
8178   if (ind->dyn_relocs != NULL)
8179     {
8180       if (dir->dyn_relocs != NULL)
8181           {
8182             struct elf_dyn_relocs **pp;
8183             struct elf_dyn_relocs *p;
8184 
8185             /* Add reloc counts against the indirect sym to the direct sym
8186                list.  Merge any entries against the same section.  */
8187             for (pp = &ind->dyn_relocs; (p = *pp) != NULL; )
8188               {
8189                 struct elf_dyn_relocs *q;
8190 
8191                 for (q = dir->dyn_relocs; q != NULL; q = q->next)
8192                     if (q->sec == p->sec)
8193                       {
8194                         q->pc_count += p->pc_count;
8195                         q->count += p->count;
8196                         *pp = p->next;
8197                         break;
8198                       }
8199                 if (q == NULL)
8200                     pp = &p->next;
8201               }
8202             *pp = dir->dyn_relocs;
8203           }
8204 
8205       dir->dyn_relocs = ind->dyn_relocs;
8206       ind->dyn_relocs = NULL;
8207     }
8208 
8209   /* Copy down any references that we may have already seen to the
8210      symbol which just became indirect.  */
8211 
8212   if (dir->versioned != versioned_hidden)
8213     dir->ref_dynamic |= ind->ref_dynamic;
8214   dir->ref_regular |= ind->ref_regular;
8215   dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
8216   dir->non_got_ref |= ind->non_got_ref;
8217   dir->needs_plt |= ind->needs_plt;
8218   dir->pointer_equality_needed |= ind->pointer_equality_needed;
8219 
8220   if (ind->root.type != bfd_link_hash_indirect)
8221     return;
8222 
8223   /* Copy over the global and procedure linkage table refcount entries.
8224      These may have been already set up by a check_relocs routine.  */
8225   htab = elf_hash_table (info);
8226   if (ind->got.refcount > htab->init_got_refcount.refcount)
8227     {
8228       if (dir->got.refcount < 0)
8229           dir->got.refcount = 0;
8230       dir->got.refcount += ind->got.refcount;
8231       ind->got.refcount = htab->init_got_refcount.refcount;
8232     }
8233 
8234   if (ind->plt.refcount > htab->init_plt_refcount.refcount)
8235     {
8236       if (dir->plt.refcount < 0)
8237           dir->plt.refcount = 0;
8238       dir->plt.refcount += ind->plt.refcount;
8239       ind->plt.refcount = htab->init_plt_refcount.refcount;
8240     }
8241 
8242   if (ind->dynindx != -1)
8243     {
8244       if (dir->dynindx != -1)
8245           _bfd_elf_strtab_delref (htab->dynstr, dir->dynstr_index);
8246       dir->dynindx = ind->dynindx;
8247       dir->dynstr_index = ind->dynstr_index;
8248       ind->dynindx = -1;
8249       ind->dynstr_index = 0;
8250     }
8251 }
8252 
8253 void
_bfd_elf_link_hash_hide_symbol(struct bfd_link_info * info,struct elf_link_hash_entry * h,bool force_local)8254 _bfd_elf_link_hash_hide_symbol (struct bfd_link_info *info,
8255                                         struct elf_link_hash_entry *h,
8256                                         bool force_local)
8257 {
8258   /* STT_GNU_IFUNC symbol must go through PLT.  */
8259   if (h->type != STT_GNU_IFUNC)
8260     {
8261       h->plt = elf_hash_table (info)->init_plt_offset;
8262       h->needs_plt = 0;
8263     }
8264   if (force_local)
8265     {
8266       h->forced_local = 1;
8267       if (h->dynindx != -1)
8268           {
8269             _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
8270                                           h->dynstr_index);
8271             h->dynindx = -1;
8272             h->dynstr_index = 0;
8273           }
8274     }
8275 }
8276 
8277 /* Hide a symbol. */
8278 
8279 void
_bfd_elf_link_hide_symbol(bfd * output_bfd,struct bfd_link_info * info,struct bfd_link_hash_entry * h)8280 _bfd_elf_link_hide_symbol (bfd *output_bfd,
8281                                  struct bfd_link_info *info,
8282                                  struct bfd_link_hash_entry *h)
8283 {
8284   if (is_elf_hash_table (info->hash))
8285     {
8286       const struct elf_backend_data *bed
8287           = get_elf_backend_data (output_bfd);
8288       struct elf_link_hash_entry *eh
8289           = (struct elf_link_hash_entry *) h;
8290       bed->elf_backend_hide_symbol (info, eh, true);
8291       eh->def_dynamic = 0;
8292       eh->ref_dynamic = 0;
8293       eh->dynamic_def = 0;
8294     }
8295 }
8296 
8297 /* Initialize an ELF linker hash table.  *TABLE has been zeroed by our
8298    caller.  */
8299 
8300 bool
_bfd_elf_link_hash_table_init(struct elf_link_hash_table * table,bfd * abfd,struct bfd_hash_entry * (* newfunc)(struct bfd_hash_entry *,struct bfd_hash_table *,const char *),unsigned int entsize,enum elf_target_id target_id)8301 _bfd_elf_link_hash_table_init
8302   (struct elf_link_hash_table *table,
8303    bfd *abfd,
8304    struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *,
8305                                               struct bfd_hash_table *,
8306                                               const char *),
8307    unsigned int entsize,
8308    enum elf_target_id target_id)
8309 {
8310   bool ret;
8311   int can_refcount = get_elf_backend_data (abfd)->can_refcount;
8312 
8313   table->init_got_refcount.refcount = can_refcount - 1;
8314   table->init_plt_refcount.refcount = can_refcount - 1;
8315   table->init_got_offset.offset = -(bfd_vma) 1;
8316   table->init_plt_offset.offset = -(bfd_vma) 1;
8317   /* The first dynamic symbol is a dummy.  */
8318   table->dynsymcount = 1;
8319 
8320   ret = _bfd_link_hash_table_init (&table->root, abfd, newfunc, entsize);
8321 
8322   table->root.type = bfd_link_elf_hash_table;
8323   table->hash_table_id = target_id;
8324   table->target_os = get_elf_backend_data (abfd)->target_os;
8325 
8326   return ret;
8327 }
8328 
8329 /* Create an ELF linker hash table.  */
8330 
8331 struct bfd_link_hash_table *
_bfd_elf_link_hash_table_create(bfd * abfd)8332 _bfd_elf_link_hash_table_create (bfd *abfd)
8333 {
8334   struct elf_link_hash_table *ret;
8335   size_t amt = sizeof (struct elf_link_hash_table);
8336 
8337   ret = (struct elf_link_hash_table *) bfd_zmalloc (amt);
8338   if (ret == NULL)
8339     return NULL;
8340 
8341   if (! _bfd_elf_link_hash_table_init (ret, abfd, _bfd_elf_link_hash_newfunc,
8342                                                sizeof (struct elf_link_hash_entry),
8343                                                GENERIC_ELF_DATA))
8344     {
8345       free (ret);
8346       return NULL;
8347     }
8348   ret->root.hash_table_free = _bfd_elf_link_hash_table_free;
8349 
8350   return &ret->root;
8351 }
8352 
8353 /* Destroy an ELF linker hash table.  */
8354 
8355 void
_bfd_elf_link_hash_table_free(bfd * obfd)8356 _bfd_elf_link_hash_table_free (bfd *obfd)
8357 {
8358   struct elf_link_hash_table *htab;
8359 
8360   htab = (struct elf_link_hash_table *) obfd->link.hash;
8361   if (htab->dynstr != NULL)
8362     _bfd_elf_strtab_free (htab->dynstr);
8363   _bfd_merge_sections_free (htab->merge_info);
8364   /* NB: htab->dynamic->contents is always allocated by bfd_realloc.  */
8365   if (htab->dynamic != NULL)
8366     free (htab->dynamic->contents);
8367   if (htab->first_hash != NULL)
8368     {
8369       bfd_hash_table_free (htab->first_hash);
8370       free (htab->first_hash);
8371     }
8372   _bfd_generic_link_hash_table_free (obfd);
8373 }
8374 
8375 /* This is a hook for the ELF emulation code in the generic linker to
8376    tell the backend linker what file name to use for the DT_NEEDED
8377    entry for a dynamic object.  */
8378 
8379 void
bfd_elf_set_dt_needed_name(bfd * abfd,const char * name)8380 bfd_elf_set_dt_needed_name (bfd *abfd, const char *name)
8381 {
8382   if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
8383       && bfd_get_format (abfd) == bfd_object)
8384     elf_dt_name (abfd) = name;
8385 }
8386 
8387 int
bfd_elf_get_dyn_lib_class(bfd * abfd)8388 bfd_elf_get_dyn_lib_class (bfd *abfd)
8389 {
8390   int lib_class;
8391   if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
8392       && bfd_get_format (abfd) == bfd_object)
8393     lib_class = elf_dyn_lib_class (abfd);
8394   else
8395     lib_class = 0;
8396   return lib_class;
8397 }
8398 
8399 void
bfd_elf_set_dyn_lib_class(bfd * abfd,enum dynamic_lib_link_class lib_class)8400 bfd_elf_set_dyn_lib_class (bfd *abfd, enum dynamic_lib_link_class lib_class)
8401 {
8402   if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
8403       && bfd_get_format (abfd) == bfd_object)
8404     elf_dyn_lib_class (abfd) = lib_class;
8405 }
8406 
8407 /* Get the list of DT_NEEDED entries for a link.  This is a hook for
8408    the linker ELF emulation code.  */
8409 
8410 struct bfd_link_needed_list *
bfd_elf_get_needed_list(bfd * abfd ATTRIBUTE_UNUSED,struct bfd_link_info * info)8411 bfd_elf_get_needed_list (bfd *abfd ATTRIBUTE_UNUSED,
8412                                struct bfd_link_info *info)
8413 {
8414   if (! is_elf_hash_table (info->hash))
8415     return NULL;
8416   return elf_hash_table (info)->needed;
8417 }
8418 
8419 /* Get the list of DT_RPATH/DT_RUNPATH entries for a link.  This is a
8420    hook for the linker ELF emulation code.  */
8421 
8422 struct bfd_link_needed_list *
bfd_elf_get_runpath_list(bfd * abfd ATTRIBUTE_UNUSED,struct bfd_link_info * info)8423 bfd_elf_get_runpath_list (bfd *abfd ATTRIBUTE_UNUSED,
8424                                 struct bfd_link_info *info)
8425 {
8426   if (! is_elf_hash_table (info->hash))
8427     return NULL;
8428   return elf_hash_table (info)->runpath;
8429 }
8430 
8431 /* Get the name actually used for a dynamic object for a link.  This
8432    is the SONAME entry if there is one.  Otherwise, it is the string
8433    passed to bfd_elf_set_dt_needed_name, or it is the filename.  */
8434 
8435 const char *
bfd_elf_get_dt_soname(bfd * abfd)8436 bfd_elf_get_dt_soname (bfd *abfd)
8437 {
8438   if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
8439       && bfd_get_format (abfd) == bfd_object)
8440     return elf_dt_name (abfd);
8441   return NULL;
8442 }
8443 
8444 /* Get the list of DT_NEEDED entries from a BFD.  This is a hook for
8445    the ELF linker emulation code.  */
8446 
8447 bool
bfd_elf_get_bfd_needed_list(bfd * abfd,struct bfd_link_needed_list ** pneeded)8448 bfd_elf_get_bfd_needed_list (bfd *abfd,
8449                                    struct bfd_link_needed_list **pneeded)
8450 {
8451   asection *s;
8452   bfd_byte *dynbuf = NULL;
8453   unsigned int elfsec;
8454   unsigned long shlink;
8455   bfd_byte *extdyn, *extdynend;
8456   size_t extdynsize;
8457   void (*swap_dyn_in) (bfd *, const void *, Elf_Internal_Dyn *);
8458 
8459   *pneeded = NULL;
8460 
8461   if (bfd_get_flavour (abfd) != bfd_target_elf_flavour
8462       || bfd_get_format (abfd) != bfd_object)
8463     return true;
8464 
8465   s = bfd_get_section_by_name (abfd, ".dynamic");
8466   if (s == NULL || s->size == 0 || (s->flags & SEC_HAS_CONTENTS) == 0)
8467     return true;
8468 
8469   if (!_bfd_elf_mmap_section_contents (abfd, s, &dynbuf))
8470     goto error_return;
8471 
8472   elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
8473   if (elfsec == SHN_BAD)
8474     goto error_return;
8475 
8476   shlink = elf_elfsections (abfd)[elfsec]->sh_link;
8477 
8478   extdynsize = get_elf_backend_data (abfd)->s->sizeof_dyn;
8479   swap_dyn_in = get_elf_backend_data (abfd)->s->swap_dyn_in;
8480 
8481   for (extdyn = dynbuf, extdynend = dynbuf + s->size;
8482        (size_t) (extdynend - extdyn) >= extdynsize;
8483        extdyn += extdynsize)
8484     {
8485       Elf_Internal_Dyn dyn;
8486 
8487       (*swap_dyn_in) (abfd, extdyn, &dyn);
8488 
8489       if (dyn.d_tag == DT_NULL)
8490           break;
8491 
8492       if (dyn.d_tag == DT_NEEDED)
8493           {
8494             const char *string;
8495             struct bfd_link_needed_list *l;
8496             unsigned int tagv = dyn.d_un.d_val;
8497             size_t amt;
8498 
8499             string = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
8500             if (string == NULL)
8501               goto error_return;
8502 
8503             amt = sizeof *l;
8504             l = (struct bfd_link_needed_list *) bfd_alloc (abfd, amt);
8505             if (l == NULL)
8506               goto error_return;
8507 
8508             l->by = abfd;
8509             l->name = string;
8510             l->next = *pneeded;
8511             *pneeded = l;
8512           }
8513     }
8514 
8515   _bfd_elf_munmap_section_contents (s, dynbuf);
8516 
8517   return true;
8518 
8519  error_return:
8520   _bfd_elf_munmap_section_contents (s, dynbuf);
8521   return false;
8522 }
8523 
8524 struct elf_symbuf_symbol
8525 {
8526   unsigned long st_name;      /* Symbol name, index in string tbl */
8527   unsigned char st_info;      /* Type and binding attributes */
8528   unsigned char st_other;     /* Visibilty, and target specific */
8529 };
8530 
8531 struct elf_symbuf_head
8532 {
8533   struct elf_symbuf_symbol *ssym;
8534   size_t count;
8535   unsigned int st_shndx;
8536 };
8537 
8538 struct elf_symbol
8539 {
8540   union
8541     {
8542       Elf_Internal_Sym *isym;
8543       struct elf_symbuf_symbol *ssym;
8544       void *p;
8545     } u;
8546   const char *name;
8547 };
8548 
8549 /* Sort references to symbols by ascending section number.  */
8550 
8551 static int
elf_sort_elf_symbol(const void * arg1,const void * arg2)8552 elf_sort_elf_symbol (const void *arg1, const void *arg2)
8553 {
8554   const Elf_Internal_Sym *s1 = *(const Elf_Internal_Sym **) arg1;
8555   const Elf_Internal_Sym *s2 = *(const Elf_Internal_Sym **) arg2;
8556 
8557   if (s1->st_shndx != s2->st_shndx)
8558     return s1->st_shndx > s2->st_shndx ? 1 : -1;
8559   /* Final sort by the address of the sym in the symbuf ensures
8560      a stable sort.  */
8561   if (s1 != s2)
8562     return s1 > s2 ? 1 : -1;
8563   return 0;
8564 }
8565 
8566 static int
elf_sym_name_compare(const void * arg1,const void * arg2)8567 elf_sym_name_compare (const void *arg1, const void *arg2)
8568 {
8569   const struct elf_symbol *s1 = (const struct elf_symbol *) arg1;
8570   const struct elf_symbol *s2 = (const struct elf_symbol *) arg2;
8571   int ret = strcmp (s1->name, s2->name);
8572   if (ret != 0)
8573     return ret;
8574   if (s1->u.p != s2->u.p)
8575     return s1->u.p > s2->u.p ? 1 : -1;
8576   return 0;
8577 }
8578 
8579 static struct elf_symbuf_head *
elf_create_symbuf(size_t symcount,Elf_Internal_Sym * isymbuf)8580 elf_create_symbuf (size_t symcount, Elf_Internal_Sym *isymbuf)
8581 {
8582   Elf_Internal_Sym **ind, **indbufend, **indbuf;
8583   struct elf_symbuf_symbol *ssym;
8584   struct elf_symbuf_head *ssymbuf, *ssymhead;
8585   size_t i, shndx_count, total_size, amt;
8586 
8587   amt = symcount * sizeof (*indbuf);
8588   indbuf = (Elf_Internal_Sym **) bfd_malloc (amt);
8589   if (indbuf == NULL)
8590     return NULL;
8591 
8592   for (ind = indbuf, i = 0; i < symcount; i++)
8593     if (isymbuf[i].st_shndx != SHN_UNDEF)
8594       *ind++ = &isymbuf[i];
8595   indbufend = ind;
8596 
8597   qsort (indbuf, indbufend - indbuf, sizeof (Elf_Internal_Sym *),
8598            elf_sort_elf_symbol);
8599 
8600   shndx_count = 0;
8601   if (indbufend > indbuf)
8602     for (ind = indbuf, shndx_count++; ind < indbufend - 1; ind++)
8603       if (ind[0]->st_shndx != ind[1]->st_shndx)
8604           shndx_count++;
8605 
8606   total_size = ((shndx_count + 1) * sizeof (*ssymbuf)
8607                     + (indbufend - indbuf) * sizeof (*ssym));
8608   ssymbuf = (struct elf_symbuf_head *) bfd_malloc (total_size);
8609   if (ssymbuf == NULL)
8610     {
8611       free (indbuf);
8612       return NULL;
8613     }
8614 
8615   ssym = (struct elf_symbuf_symbol *) (ssymbuf + shndx_count + 1);
8616   ssymbuf->ssym = NULL;
8617   ssymbuf->count = shndx_count;
8618   ssymbuf->st_shndx = 0;
8619   for (ssymhead = ssymbuf, ind = indbuf; ind < indbufend; ssym++, ind++)
8620     {
8621       if (ind == indbuf || ssymhead->st_shndx != (*ind)->st_shndx)
8622           {
8623             ssymhead++;
8624             ssymhead->ssym = ssym;
8625             ssymhead->count = 0;
8626             ssymhead->st_shndx = (*ind)->st_shndx;
8627           }
8628       ssym->st_name = (*ind)->st_name;
8629       ssym->st_info = (*ind)->st_info;
8630       ssym->st_other = (*ind)->st_other;
8631       ssymhead->count++;
8632     }
8633   BFD_ASSERT ((size_t) (ssymhead - ssymbuf) == shndx_count
8634                 && (uintptr_t) ssym - (uintptr_t) ssymbuf == total_size);
8635 
8636   free (indbuf);
8637   return ssymbuf;
8638 }
8639 
8640 /* Check if 2 sections define the same set of local and global
8641    symbols.  */
8642 
8643 static bool
bfd_elf_match_symbols_in_sections(asection * sec1,asection * sec2,struct bfd_link_info * info)8644 bfd_elf_match_symbols_in_sections (asection *sec1, asection *sec2,
8645                                            struct bfd_link_info *info)
8646 {
8647   bfd *bfd1, *bfd2;
8648   const struct elf_backend_data *bed1, *bed2;
8649   Elf_Internal_Shdr *hdr1, *hdr2;
8650   size_t symcount1, symcount2;
8651   Elf_Internal_Sym *isymbuf1, *isymbuf2;
8652   struct elf_symbuf_head *ssymbuf1, *ssymbuf2;
8653   Elf_Internal_Sym *isym, *isymend;
8654   struct elf_symbol *symtable1 = NULL, *symtable2 = NULL;
8655   size_t count1, count2, sec_count1, sec_count2, i;
8656   unsigned int shndx1, shndx2;
8657   bool result;
8658   bool ignore_section_symbol_p;
8659 
8660   bfd1 = sec1->owner;
8661   bfd2 = sec2->owner;
8662 
8663   /* Both sections have to be in ELF.  */
8664   if (bfd_get_flavour (bfd1) != bfd_target_elf_flavour
8665       || bfd_get_flavour (bfd2) != bfd_target_elf_flavour)
8666     return false;
8667 
8668   if (elf_section_type (sec1) != elf_section_type (sec2))
8669     return false;
8670 
8671   shndx1 = _bfd_elf_section_from_bfd_section (bfd1, sec1);
8672   shndx2 = _bfd_elf_section_from_bfd_section (bfd2, sec2);
8673   if (shndx1 == SHN_BAD || shndx2 == SHN_BAD)
8674     return false;
8675 
8676   bed1 = get_elf_backend_data (bfd1);
8677   bed2 = get_elf_backend_data (bfd2);
8678   hdr1 = &elf_tdata (bfd1)->symtab_hdr;
8679   symcount1 = hdr1->sh_size / bed1->s->sizeof_sym;
8680   hdr2 = &elf_tdata (bfd2)->symtab_hdr;
8681   symcount2 = hdr2->sh_size / bed2->s->sizeof_sym;
8682 
8683   if (symcount1 == 0 || symcount2 == 0)
8684     return false;
8685 
8686   result = false;
8687   isymbuf1 = NULL;
8688   isymbuf2 = NULL;
8689   ssymbuf1 = (struct elf_symbuf_head *) elf_tdata (bfd1)->symbuf;
8690   ssymbuf2 = (struct elf_symbuf_head *) elf_tdata (bfd2)->symbuf;
8691 
8692   /* Ignore section symbols only when matching non-debugging sections
8693      or linkonce section with comdat section.  */
8694   ignore_section_symbol_p
8695     = ((sec1->flags & SEC_DEBUGGING) == 0
8696        || ((elf_section_flags (sec1) & SHF_GROUP)
8697              != (elf_section_flags (sec2) & SHF_GROUP)));
8698 
8699   if (ssymbuf1 == NULL)
8700     {
8701       isymbuf1 = bfd_elf_get_elf_syms (bfd1, hdr1, symcount1, 0,
8702                                                NULL, NULL, NULL);
8703       if (isymbuf1 == NULL)
8704           goto done;
8705 
8706       if (info != NULL && !info->reduce_memory_overheads)
8707           {
8708             ssymbuf1 = elf_create_symbuf (symcount1, isymbuf1);
8709             elf_tdata (bfd1)->symbuf = ssymbuf1;
8710           }
8711     }
8712 
8713   if (ssymbuf1 == NULL || ssymbuf2 == NULL)
8714     {
8715       isymbuf2 = bfd_elf_get_elf_syms (bfd2, hdr2, symcount2, 0,
8716                                                NULL, NULL, NULL);
8717       if (isymbuf2 == NULL)
8718           goto done;
8719 
8720       if (ssymbuf1 != NULL && info != NULL && !info->reduce_memory_overheads)
8721           {
8722             ssymbuf2 = elf_create_symbuf (symcount2, isymbuf2);
8723             elf_tdata (bfd2)->symbuf = ssymbuf2;
8724           }
8725     }
8726 
8727   if (ssymbuf1 != NULL && ssymbuf2 != NULL)
8728     {
8729       /* Optimized faster version.  */
8730       size_t lo, hi, mid;
8731       struct elf_symbol *symp;
8732       struct elf_symbuf_symbol *ssym, *ssymend;
8733 
8734       lo = 0;
8735       hi = ssymbuf1->count;
8736       ssymbuf1++;
8737       count1 = 0;
8738       sec_count1 = 0;
8739       while (lo < hi)
8740           {
8741             mid = (lo + hi) / 2;
8742             if (shndx1 < ssymbuf1[mid].st_shndx)
8743               hi = mid;
8744             else if (shndx1 > ssymbuf1[mid].st_shndx)
8745               lo = mid + 1;
8746             else
8747               {
8748                 count1 = ssymbuf1[mid].count;
8749                 ssymbuf1 += mid;
8750                 break;
8751               }
8752           }
8753       if (ignore_section_symbol_p)
8754           {
8755             for (i = 0; i < count1; i++)
8756               if (ELF_ST_TYPE (ssymbuf1->ssym[i].st_info) == STT_SECTION)
8757                 sec_count1++;
8758             count1 -= sec_count1;
8759           }
8760 
8761       lo = 0;
8762       hi = ssymbuf2->count;
8763       ssymbuf2++;
8764       count2 = 0;
8765       sec_count2 = 0;
8766       while (lo < hi)
8767           {
8768             mid = (lo + hi) / 2;
8769             if (shndx2 < ssymbuf2[mid].st_shndx)
8770               hi = mid;
8771             else if (shndx2 > ssymbuf2[mid].st_shndx)
8772               lo = mid + 1;
8773             else
8774               {
8775                 count2 = ssymbuf2[mid].count;
8776                 ssymbuf2 += mid;
8777                 break;
8778               }
8779           }
8780       if (ignore_section_symbol_p)
8781           {
8782             for (i = 0; i < count2; i++)
8783               if (ELF_ST_TYPE (ssymbuf2->ssym[i].st_info) == STT_SECTION)
8784                 sec_count2++;
8785             count2 -= sec_count2;
8786           }
8787 
8788       if (count1 == 0 || count2 == 0 || count1 != count2)
8789           goto done;
8790 
8791       symtable1
8792           = (struct elf_symbol *) bfd_malloc (count1 * sizeof (*symtable1));
8793       symtable2
8794           = (struct elf_symbol *) bfd_malloc (count2 * sizeof (*symtable2));
8795       if (symtable1 == NULL || symtable2 == NULL)
8796           goto done;
8797 
8798       symp = symtable1;
8799       for (ssym = ssymbuf1->ssym, ssymend = ssym + count1 + sec_count1;
8800              ssym < ssymend; ssym++)
8801           if (sec_count1 == 0
8802               || ELF_ST_TYPE (ssym->st_info) != STT_SECTION)
8803             {
8804               symp->u.ssym = ssym;
8805               symp->name = bfd_elf_string_from_elf_section (bfd1,
8806                                                                         hdr1->sh_link,
8807                                                                         ssym->st_name);
8808               symp++;
8809             }
8810 
8811       symp = symtable2;
8812       for (ssym = ssymbuf2->ssym, ssymend = ssym + count2 + sec_count2;
8813              ssym < ssymend; ssym++)
8814           if (sec_count2 == 0
8815               || ELF_ST_TYPE (ssym->st_info) != STT_SECTION)
8816             {
8817               symp->u.ssym = ssym;
8818               symp->name = bfd_elf_string_from_elf_section (bfd2,
8819                                                                         hdr2->sh_link,
8820                                                                         ssym->st_name);
8821               symp++;
8822             }
8823 
8824       /* Sort symbol by name.  */
8825       qsort (symtable1, count1, sizeof (struct elf_symbol),
8826                elf_sym_name_compare);
8827       qsort (symtable2, count1, sizeof (struct elf_symbol),
8828                elf_sym_name_compare);
8829 
8830       for (i = 0; i < count1; i++)
8831           /* Two symbols must have the same binding, type and name.  */
8832           if (symtable1 [i].u.ssym->st_info != symtable2 [i].u.ssym->st_info
8833               || symtable1 [i].u.ssym->st_other != symtable2 [i].u.ssym->st_other
8834               || strcmp (symtable1 [i].name, symtable2 [i].name) != 0)
8835             goto done;
8836 
8837       result = true;
8838       goto done;
8839     }
8840 
8841   symtable1 = (struct elf_symbol *)
8842       bfd_malloc (symcount1 * sizeof (struct elf_symbol));
8843   symtable2 = (struct elf_symbol *)
8844       bfd_malloc (symcount2 * sizeof (struct elf_symbol));
8845   if (symtable1 == NULL || symtable2 == NULL)
8846     goto done;
8847 
8848   /* Count definitions in the section.  */
8849   count1 = 0;
8850   for (isym = isymbuf1, isymend = isym + symcount1; isym < isymend; isym++)
8851     if (isym->st_shndx == shndx1
8852           && (!ignore_section_symbol_p
8853               || ELF_ST_TYPE (isym->st_info) != STT_SECTION))
8854       symtable1[count1++].u.isym = isym;
8855 
8856   count2 = 0;
8857   for (isym = isymbuf2, isymend = isym + symcount2; isym < isymend; isym++)
8858     if (isym->st_shndx == shndx2
8859           && (!ignore_section_symbol_p
8860               || ELF_ST_TYPE (isym->st_info) != STT_SECTION))
8861       symtable2[count2++].u.isym = isym;
8862 
8863   if (count1 == 0 || count2 == 0 || count1 != count2)
8864     goto done;
8865 
8866   for (i = 0; i < count1; i++)
8867     symtable1[i].name
8868       = bfd_elf_string_from_elf_section (bfd1, hdr1->sh_link,
8869                                                    symtable1[i].u.isym->st_name);
8870 
8871   for (i = 0; i < count2; i++)
8872     symtable2[i].name
8873       = bfd_elf_string_from_elf_section (bfd2, hdr2->sh_link,
8874                                                    symtable2[i].u.isym->st_name);
8875 
8876   /* Sort symbol by name.  */
8877   qsort (symtable1, count1, sizeof (struct elf_symbol),
8878            elf_sym_name_compare);
8879   qsort (symtable2, count1, sizeof (struct elf_symbol),
8880            elf_sym_name_compare);
8881 
8882   for (i = 0; i < count1; i++)
8883     /* Two symbols must have the same binding, type and name.  */
8884     if (symtable1 [i].u.isym->st_info != symtable2 [i].u.isym->st_info
8885           || symtable1 [i].u.isym->st_other != symtable2 [i].u.isym->st_other
8886           || strcmp (symtable1 [i].name, symtable2 [i].name) != 0)
8887       goto done;
8888 
8889   result = true;
8890 
8891  done:
8892   free (symtable1);
8893   free (symtable2);
8894   free (isymbuf1);
8895   free (isymbuf2);
8896 
8897   return result;
8898 }
8899 
8900 /* Return TRUE if 2 section types are compatible.  */
8901 
8902 bool
_bfd_elf_match_sections_by_type(bfd * abfd,const asection * asec,bfd * bbfd,const asection * bsec)8903 _bfd_elf_match_sections_by_type (bfd *abfd, const asection *asec,
8904                                          bfd *bbfd, const asection *bsec)
8905 {
8906   if (asec == NULL
8907       || bsec == NULL
8908       || abfd->xvec->flavour != bfd_target_elf_flavour
8909       || bbfd->xvec->flavour != bfd_target_elf_flavour)
8910     return true;
8911 
8912   return elf_section_type (asec) == elf_section_type (bsec);
8913 }
8914 
8915 /* Final phase of ELF linker.  */
8916 
8917 /* A structure we use to avoid passing large numbers of arguments.  */
8918 
8919 struct elf_final_link_info
8920 {
8921   /* General link information.  */
8922   struct bfd_link_info *info;
8923   /* Output BFD.  */
8924   bfd *output_bfd;
8925   /* Symbol string table.  */
8926   struct elf_strtab_hash *symstrtab;
8927   /* .hash section.  */
8928   asection *hash_sec;
8929   /* symbol version section (.gnu.version).  */
8930   asection *symver_sec;
8931   /* Buffer large enough to hold contents of any section.  */
8932   bfd_byte *contents;
8933   /* Buffer large enough to hold external relocs of any section.  */
8934   void *external_relocs;
8935   /* Buffer large enough to hold internal relocs of any section.  */
8936   Elf_Internal_Rela *internal_relocs;
8937   /* Buffer large enough to hold external local symbols of any input
8938      BFD.  */
8939   bfd_byte *external_syms;
8940   /* And a buffer for symbol section indices.  */
8941   Elf_External_Sym_Shndx *locsym_shndx;
8942   /* Buffer large enough to hold internal local symbols of any input
8943      BFD.  */
8944   Elf_Internal_Sym *internal_syms;
8945   /* Array large enough to hold a symbol index for each local symbol
8946      of any input BFD.  */
8947   long *indices;
8948   /* Array large enough to hold a section pointer for each local
8949      symbol of any input BFD.  */
8950   asection **sections;
8951   /* Buffer for SHT_SYMTAB_SHNDX section.  */
8952   Elf_External_Sym_Shndx *symshndxbuf;
8953   /* Number of STT_FILE syms seen.  */
8954   size_t filesym_count;
8955   /* Local symbol hash table.  */
8956   struct bfd_hash_table local_hash_table;
8957 };
8958 
8959 struct local_hash_entry
8960 {
8961   /* Base hash table entry structure.  */
8962   struct bfd_hash_entry root;
8963   /* Size of the local symbol name.  */
8964   size_t size;
8965   /* Number of the duplicated local symbol names.  */
8966   long count;
8967 };
8968 
8969 /* Create an entry in the local symbol hash table.  */
8970 
8971 static struct bfd_hash_entry *
local_hash_newfunc(struct bfd_hash_entry * entry,struct bfd_hash_table * table,const char * string)8972 local_hash_newfunc (struct bfd_hash_entry *entry,
8973                         struct bfd_hash_table *table,
8974                         const char *string)
8975 {
8976 
8977   /* Allocate the structure if it has not already been allocated by a
8978      subclass.  */
8979   if (entry == NULL)
8980     {
8981       entry = bfd_hash_allocate (table,
8982                                          sizeof (struct local_hash_entry));
8983       if (entry == NULL)
8984         return entry;
8985     }
8986 
8987   /* Call the allocation method of the superclass.  */
8988   entry = bfd_hash_newfunc (entry, table, string);
8989   if (entry != NULL)
8990     {
8991       ((struct local_hash_entry *) entry)->count = 0;
8992       ((struct local_hash_entry *) entry)->size = 0;
8993     }
8994 
8995   return entry;
8996 }
8997 
8998 /* This struct is used to pass information to elf_link_output_extsym.  */
8999 
9000 struct elf_outext_info
9001 {
9002   bool failed;
9003   bool localsyms;
9004   bool file_sym_done;
9005   struct elf_final_link_info *flinfo;
9006 };
9007 
9008 
9009 /* Support for evaluating a complex relocation.
9010 
9011    Complex relocations are generalized, self-describing relocations.  The
9012    implementation of them consists of two parts: complex symbols, and the
9013    relocations themselves.
9014 
9015    The relocations use a reserved elf-wide relocation type code (R_RELC
9016    external / BFD_RELOC_RELC internal) and an encoding of relocation field
9017    information (start bit, end bit, word width, etc) into the addend.  This
9018    information is extracted from CGEN-generated operand tables within gas.
9019 
9020    Complex symbols are mangled symbols (STT_RELC external / BSF_RELC
9021    internal) representing prefix-notation expressions, including but not
9022    limited to those sorts of expressions normally encoded as addends in the
9023    addend field.  The symbol mangling format is:
9024 
9025    <node> := <literal>
9026             |  <unary-operator> ':' <node>
9027             |  <binary-operator> ':' <node> ':' <node>
9028             ;
9029 
9030    <literal> := 's' <digits=N> ':' <N character symbol name>
9031                |  'S' <digits=N> ':' <N character section name>
9032                |  '#' <hexdigits>
9033                ;
9034 
9035    <binary-operator> := as in C
9036    <unary-operator> := as in C, plus "0-" for unambiguous negation.  */
9037 
9038 static void
set_symbol_value(bfd * bfd_with_globals,Elf_Internal_Sym * isymbuf,size_t locsymcount,size_t symidx,bfd_vma val)9039 set_symbol_value (bfd *bfd_with_globals,
9040                       Elf_Internal_Sym *isymbuf,
9041                       size_t locsymcount,
9042                       size_t symidx,
9043                       bfd_vma val)
9044 {
9045   struct elf_link_hash_entry **sym_hashes;
9046   struct elf_link_hash_entry *h;
9047   size_t extsymoff = locsymcount;
9048 
9049   if (symidx < locsymcount)
9050     {
9051       Elf_Internal_Sym *sym;
9052 
9053       sym = isymbuf + symidx;
9054       if (ELF_ST_BIND (sym->st_info) == STB_LOCAL)
9055           {
9056             /* It is a local symbol: move it to the
9057                "absolute" section and give it a value.  */
9058             sym->st_shndx = SHN_ABS;
9059             sym->st_value = val;
9060             return;
9061           }
9062       BFD_ASSERT (elf_bad_symtab (bfd_with_globals));
9063       extsymoff = 0;
9064     }
9065 
9066   /* It is a global symbol: set its link type
9067      to "defined" and give it a value.  */
9068 
9069   sym_hashes = elf_sym_hashes (bfd_with_globals);
9070   h = sym_hashes [symidx - extsymoff];
9071   while (h->root.type == bfd_link_hash_indirect
9072            || h->root.type == bfd_link_hash_warning)
9073     h = (struct elf_link_hash_entry *) h->root.u.i.link;
9074   h->root.type = bfd_link_hash_defined;
9075   h->root.u.def.value = val;
9076   h->root.u.def.section = bfd_abs_section_ptr;
9077 }
9078 
9079 static bool
resolve_symbol(const char * name,bfd * input_bfd,struct elf_final_link_info * flinfo,bfd_vma * result,Elf_Internal_Sym * isymbuf,size_t locsymcount)9080 resolve_symbol (const char *name,
9081                     bfd *input_bfd,
9082                     struct elf_final_link_info *flinfo,
9083                     bfd_vma *result,
9084                     Elf_Internal_Sym *isymbuf,
9085                     size_t locsymcount)
9086 {
9087   Elf_Internal_Sym *sym;
9088   struct bfd_link_hash_entry *global_entry;
9089   const char *candidate = NULL;
9090   Elf_Internal_Shdr *symtab_hdr;
9091   size_t i;
9092 
9093   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
9094 
9095   for (i = 0; i < locsymcount; ++ i)
9096     {
9097       sym = isymbuf + i;
9098 
9099       if (ELF_ST_BIND (sym->st_info) != STB_LOCAL)
9100           continue;
9101 
9102       candidate = bfd_elf_string_from_elf_section (input_bfd,
9103                                                                symtab_hdr->sh_link,
9104                                                                sym->st_name);
9105 #ifdef DEBUG
9106       printf ("Comparing string: '%s' vs. '%s' = 0x%lx\n",
9107                 name, candidate, (unsigned long) sym->st_value);
9108 #endif
9109       if (candidate && strcmp (candidate, name) == 0)
9110           {
9111             asection *sec = flinfo->sections [i];
9112 
9113             *result = _bfd_elf_rel_local_sym (input_bfd, sym, &sec, 0);
9114             *result += sec->output_offset + sec->output_section->vma;
9115 #ifdef DEBUG
9116             printf ("Found symbol with value %8.8lx\n",
9117                       (unsigned long) *result);
9118 #endif
9119             return true;
9120           }
9121     }
9122 
9123   /* Hmm, haven't found it yet. perhaps it is a global.  */
9124   global_entry = bfd_link_hash_lookup (flinfo->info->hash, name,
9125                                                false, false, true);
9126   if (!global_entry)
9127     return false;
9128 
9129   if (global_entry->type == bfd_link_hash_defined
9130       || global_entry->type == bfd_link_hash_defweak)
9131     {
9132       *result = (global_entry->u.def.value
9133                      + global_entry->u.def.section->output_section->vma
9134                      + global_entry->u.def.section->output_offset);
9135 #ifdef DEBUG
9136       printf ("Found GLOBAL symbol '%s' with value %8.8lx\n",
9137                 global_entry->root.string, (unsigned long) *result);
9138 #endif
9139       return true;
9140     }
9141 
9142   return false;
9143 }
9144 
9145 /* Looks up NAME in SECTIONS.  If found sets RESULT to NAME's address (in
9146    bytes) and returns TRUE, otherwise returns FALSE.  Accepts pseudo-section
9147    names like "foo.end" which is the end address of section "foo".  */
9148 
9149 static bool
resolve_section(const char * name,asection * sections,bfd_vma * result,bfd * abfd)9150 resolve_section (const char *name,
9151                      asection *sections,
9152                      bfd_vma *result,
9153                      bfd * abfd)
9154 {
9155   asection *curr;
9156   unsigned int len;
9157 
9158   for (curr = sections; curr; curr = curr->next)
9159     if (strcmp (curr->name, name) == 0)
9160       {
9161           *result = curr->vma;
9162           return true;
9163       }
9164 
9165   /* Hmm. still haven't found it. try pseudo-section names.  */
9166   /* FIXME: This could be coded more efficiently...  */
9167   for (curr = sections; curr; curr = curr->next)
9168     {
9169       len = strlen (curr->name);
9170       if (len > strlen (name))
9171           continue;
9172 
9173       if (strncmp (curr->name, name, len) == 0)
9174           {
9175             if (startswith (name + len, ".end"))
9176               {
9177                 *result = (curr->vma
9178                                + curr->size / bfd_octets_per_byte (abfd, curr));
9179                 return true;
9180               }
9181 
9182             /* Insert more pseudo-section names here, if you like.  */
9183           }
9184     }
9185 
9186   return false;
9187 }
9188 
9189 static void
undefined_reference(const char * reftype,const char * name)9190 undefined_reference (const char *reftype, const char *name)
9191 {
9192   /* xgettext:c-format */
9193   _bfd_error_handler (_("undefined %s reference in complex symbol: %s"),
9194                           reftype, name);
9195   bfd_set_error (bfd_error_bad_value);
9196 }
9197 
9198 static bool
eval_symbol(bfd_vma * result,const char ** symp,bfd * input_bfd,struct elf_final_link_info * flinfo,bfd_vma dot,Elf_Internal_Sym * isymbuf,size_t locsymcount,int signed_p)9199 eval_symbol (bfd_vma *result,
9200                const char **symp,
9201                bfd *input_bfd,
9202                struct elf_final_link_info *flinfo,
9203                bfd_vma dot,
9204                Elf_Internal_Sym *isymbuf,
9205                size_t locsymcount,
9206                int signed_p)
9207 {
9208   size_t len;
9209   size_t symlen;
9210   bfd_vma a;
9211   bfd_vma b;
9212   char symbuf[4096];
9213   const char *sym = *symp;
9214   const char *symend;
9215   bool symbol_is_section = false;
9216 
9217   len = strlen (sym);
9218   symend = sym + len;
9219 
9220   if (len < 1 || len > sizeof (symbuf))
9221     {
9222       bfd_set_error (bfd_error_invalid_operation);
9223       return false;
9224     }
9225 
9226   switch (* sym)
9227     {
9228     case '.':
9229       *result = dot;
9230       *symp = sym + 1;
9231       return true;
9232 
9233     case '#':
9234       ++sym;
9235       *result = strtoul (sym, (char **) symp, 16);
9236       return true;
9237 
9238     case 'S':
9239       symbol_is_section = true;
9240       /* Fall through.  */
9241     case 's':
9242       ++sym;
9243       symlen = strtol (sym, (char **) symp, 10);
9244       sym = *symp + 1; /* Skip the trailing ':'.  */
9245 
9246       if (symend < sym || symlen + 1 > sizeof (symbuf))
9247           {
9248             bfd_set_error (bfd_error_invalid_operation);
9249             return false;
9250           }
9251 
9252       memcpy (symbuf, sym, symlen);
9253       symbuf[symlen] = '\0';
9254       *symp = sym + symlen;
9255 
9256       /* Is it always possible, with complex symbols, that gas "mis-guessed"
9257            the symbol as a section, or vice-versa. so we're pretty liberal in our
9258            interpretation here; section means "try section first", not "must be a
9259            section", and likewise with symbol.  */
9260 
9261       if (symbol_is_section)
9262           {
9263             if (!resolve_section (symbuf, flinfo->output_bfd->sections, result, input_bfd)
9264                 && !resolve_symbol (symbuf, input_bfd, flinfo, result,
9265                                           isymbuf, locsymcount))
9266               {
9267                 undefined_reference ("section", symbuf);
9268                 return false;
9269               }
9270           }
9271       else
9272           {
9273             if (!resolve_symbol (symbuf, input_bfd, flinfo, result,
9274                                      isymbuf, locsymcount)
9275                 && !resolve_section (symbuf, flinfo->output_bfd->sections,
9276                                            result, input_bfd))
9277               {
9278                 undefined_reference ("symbol", symbuf);
9279                 return false;
9280               }
9281           }
9282 
9283       return true;
9284 
9285       /* All that remains are operators.  */
9286 
9287 #define UNARY_OP(op)                                                            \
9288   if (startswith (sym, #op))                                          \
9289     {                                                                           \
9290       sym += strlen (#op);                                            \
9291       if (*sym == ':')                                                          \
9292           ++sym;                                                                \
9293       *symp = sym;                                                    \
9294       if (!eval_symbol (&a, symp, input_bfd, flinfo, dot,   \
9295                               isymbuf, locsymcount, signed_p))        \
9296           return false;                                                         \
9297       if (signed_p)                                                   \
9298           *result = op ((bfd_signed_vma) a);                          \
9299       else                                                                      \
9300           *result = op a;                                                       \
9301       return true;                                                    \
9302     }
9303 
9304 #define BINARY_OP_HEAD(op)                                            \
9305   if (startswith (sym, #op))                                          \
9306     {                                                                           \
9307       sym += strlen (#op);                                            \
9308       if (*sym == ':')                                                          \
9309           ++sym;                                                                \
9310       *symp = sym;                                                    \
9311       if (!eval_symbol (&a, symp, input_bfd, flinfo, dot,   \
9312                               isymbuf, locsymcount, signed_p))        \
9313           return false;                                                         \
9314       ++*symp;                                                                  \
9315       if (!eval_symbol (&b, symp, input_bfd, flinfo, dot,   \
9316                               isymbuf, locsymcount, signed_p))        \
9317           return false;
9318 #define BINARY_OP_TAIL(op)                                            \
9319       if (signed_p)                                                   \
9320           *result = ((bfd_signed_vma) a) op ((bfd_signed_vma) b);     \
9321       else                                                                      \
9322           *result = a op b;                                           \
9323       return true;                                                    \
9324     }
9325 #define BINARY_OP(op) BINARY_OP_HEAD(op) BINARY_OP_TAIL(op)
9326 
9327     default:
9328       UNARY_OP  (0-);
9329       BINARY_OP_HEAD (<<);
9330       if (b >= sizeof (a) * CHAR_BIT)
9331           {
9332             *result = 0;
9333             return true;
9334           }
9335       signed_p = 0;
9336       BINARY_OP_TAIL (<<);
9337       BINARY_OP_HEAD (>>);
9338       if (b >= sizeof (a) * CHAR_BIT)
9339           {
9340             *result = signed_p && (bfd_signed_vma) a < 0 ? -1 : 0;
9341             return true;
9342           }
9343       BINARY_OP_TAIL (>>);
9344       BINARY_OP (==);
9345       BINARY_OP (!=);
9346       BINARY_OP (<=);
9347       BINARY_OP (>=);
9348       BINARY_OP (&&);
9349       BINARY_OP (||);
9350       UNARY_OP  (~);
9351       UNARY_OP  (!);
9352       BINARY_OP (*);
9353       BINARY_OP_HEAD (/);
9354       if (b == 0)
9355           {
9356             _bfd_error_handler (_("division by zero"));
9357             bfd_set_error (bfd_error_bad_value);
9358             return false;
9359           }
9360       BINARY_OP_TAIL (/);
9361       BINARY_OP_HEAD (%);
9362       if (b == 0)
9363           {
9364             _bfd_error_handler (_("division by zero"));
9365             bfd_set_error (bfd_error_bad_value);
9366             return false;
9367           }
9368       BINARY_OP_TAIL (%);
9369       BINARY_OP (^);
9370       BINARY_OP (|);
9371       BINARY_OP (&);
9372       BINARY_OP (+);
9373       BINARY_OP (-);
9374       BINARY_OP (<);
9375       BINARY_OP (>);
9376 #undef UNARY_OP
9377 #undef BINARY_OP
9378       _bfd_error_handler (_("unknown operator '%c' in complex symbol"), * sym);
9379       bfd_set_error (bfd_error_invalid_operation);
9380       return false;
9381     }
9382 }
9383 
9384 static void
put_value(bfd_vma size,unsigned long chunksz,bfd * input_bfd,bfd_vma x,bfd_byte * location)9385 put_value (bfd_vma size,
9386              unsigned long chunksz,
9387              bfd *input_bfd,
9388              bfd_vma x,
9389              bfd_byte *location)
9390 {
9391   location += (size - chunksz);
9392 
9393   for (; size; size -= chunksz, location -= chunksz)
9394     {
9395       switch (chunksz)
9396           {
9397           case 1:
9398             bfd_put_8 (input_bfd, x, location);
9399             x >>= 8;
9400             break;
9401           case 2:
9402             bfd_put_16 (input_bfd, x, location);
9403             x >>= 16;
9404             break;
9405           case 4:
9406             bfd_put_32 (input_bfd, x, location);
9407             /* Computed this way because x >>= 32 is undefined if x is a 32-bit value.  */
9408             x >>= 16;
9409             x >>= 16;
9410             break;
9411 #ifdef BFD64
9412           case 8:
9413             bfd_put_64 (input_bfd, x, location);
9414             /* Computed this way because x >>= 64 is undefined if x is a 64-bit value.  */
9415             x >>= 32;
9416             x >>= 32;
9417             break;
9418 #endif
9419           default:
9420             abort ();
9421             break;
9422           }
9423     }
9424 }
9425 
9426 static bfd_vma
get_value(bfd_vma size,unsigned long chunksz,bfd * input_bfd,bfd_byte * location)9427 get_value (bfd_vma size,
9428              unsigned long chunksz,
9429              bfd *input_bfd,
9430              bfd_byte *location)
9431 {
9432   int shift;
9433   bfd_vma x = 0;
9434 
9435   /* Sanity checks.  */
9436   BFD_ASSERT (chunksz <= sizeof (x)
9437                 && size >= chunksz
9438                 && chunksz != 0
9439                 && (size % chunksz) == 0
9440                 && input_bfd != NULL
9441                 && location != NULL);
9442 
9443   if (chunksz == sizeof (x))
9444     {
9445       BFD_ASSERT (size == chunksz);
9446 
9447       /* Make sure that we do not perform an undefined shift operation.
9448            We know that size == chunksz so there will only be one iteration
9449            of the loop below.  */
9450       shift = 0;
9451     }
9452   else
9453     shift = 8 * chunksz;
9454 
9455   for (; size; size -= chunksz, location += chunksz)
9456     {
9457       switch (chunksz)
9458           {
9459           case 1:
9460             x = (x << shift) | bfd_get_8 (input_bfd, location);
9461             break;
9462           case 2:
9463             x = (x << shift) | bfd_get_16 (input_bfd, location);
9464             break;
9465           case 4:
9466             x = (x << shift) | bfd_get_32 (input_bfd, location);
9467             break;
9468 #ifdef BFD64
9469           case 8:
9470             x = (x << shift) | bfd_get_64 (input_bfd, location);
9471             break;
9472 #endif
9473           default:
9474             abort ();
9475           }
9476     }
9477   return x;
9478 }
9479 
9480 static void
decode_complex_addend(unsigned long * start,unsigned long * oplen,unsigned long * len,unsigned long * wordsz,unsigned long * chunksz,unsigned long * lsb0_p,unsigned long * signed_p,unsigned long * trunc_p,unsigned long encoded)9481 decode_complex_addend (unsigned long *start,   /* in bits */
9482                            unsigned long *oplen,   /* in bits */
9483                            unsigned long *len,     /* in bits */
9484                            unsigned long *wordsz,  /* in bytes */
9485                            unsigned long *chunksz, /* in bytes */
9486                            unsigned long *lsb0_p,
9487                            unsigned long *signed_p,
9488                            unsigned long *trunc_p,
9489                            unsigned long encoded)
9490 {
9491   * start     =      encoded  & 0x3F;
9492   * len         = (encoded >>  6) & 0x3F;
9493   * oplen     = (encoded >> 12) & 0x3F;
9494   * wordsz    = (encoded >> 18) & 0xF;
9495   * chunksz   = (encoded >> 22) & 0xF;
9496   * lsb0_p    = (encoded >> 27) & 1;
9497   * signed_p  = (encoded >> 28) & 1;
9498   * trunc_p   = (encoded >> 29) & 1;
9499 }
9500 
9501 bfd_reloc_status_type
bfd_elf_perform_complex_relocation(bfd * input_bfd,asection * input_section,bfd_byte * contents,Elf_Internal_Rela * rel,bfd_vma relocation)9502 bfd_elf_perform_complex_relocation (bfd *input_bfd,
9503                                             asection *input_section,
9504                                             bfd_byte *contents,
9505                                             Elf_Internal_Rela *rel,
9506                                             bfd_vma relocation)
9507 {
9508   bfd_vma shift, x, mask;
9509   unsigned long start, oplen, len, wordsz, chunksz, lsb0_p, signed_p, trunc_p;
9510   bfd_reloc_status_type r;
9511   bfd_size_type octets;
9512 
9513   /*  Perform this reloc, since it is complex.
9514       (this is not to say that it necessarily refers to a complex
9515       symbol; merely that it is a self-describing CGEN based reloc.
9516       i.e. the addend has the complete reloc information (bit start, end,
9517       word size, etc) encoded within it.).  */
9518 
9519   decode_complex_addend (&start, &oplen, &len, &wordsz,
9520                                &chunksz, &lsb0_p, &signed_p,
9521                                &trunc_p, rel->r_addend);
9522 
9523   mask = (((1L << (len - 1)) - 1) << 1) | 1;
9524 
9525   if (lsb0_p)
9526     shift = (start + 1) - len;
9527   else
9528     shift = (8 * wordsz) - (start + len);
9529 
9530   octets = rel->r_offset * bfd_octets_per_byte (input_bfd, input_section);
9531   x = get_value (wordsz, chunksz, input_bfd, contents + octets);
9532 
9533 #ifdef DEBUG
9534   printf ("Doing complex reloc: "
9535             "lsb0? %ld, signed? %ld, trunc? %ld, wordsz %ld, "
9536             "chunksz %ld, start %ld, len %ld, oplen %ld\n"
9537             "    dest: %8.8lx, mask: %8.8lx, reloc: %8.8lx\n",
9538             lsb0_p, signed_p, trunc_p, wordsz, chunksz, start, len,
9539             oplen, (unsigned long) x, (unsigned long) mask,
9540             (unsigned long) relocation);
9541 #endif
9542 
9543   r = bfd_reloc_ok;
9544   if (! trunc_p)
9545     /* Now do an overflow check.  */
9546     r = bfd_check_overflow ((signed_p
9547                                    ? complain_overflow_signed
9548                                    : complain_overflow_unsigned),
9549                                   len, 0, (8 * wordsz),
9550                                   relocation);
9551 
9552   /* Do the deed.  */
9553   x = (x & ~(mask << shift)) | ((relocation & mask) << shift);
9554 
9555 #ifdef DEBUG
9556   printf ("           relocation: %8.8lx\n"
9557             "         shifted mask: %8.8lx\n"
9558             " shifted/masked reloc: %8.8lx\n"
9559             "               result: %8.8lx\n",
9560             (unsigned long) relocation, (unsigned long) (mask << shift),
9561             (unsigned long) ((relocation & mask) << shift), (unsigned long) x);
9562 #endif
9563   put_value (wordsz, chunksz, input_bfd, x, contents + octets);
9564   return r;
9565 }
9566 
9567 /* Functions to read r_offset from external (target order) reloc
9568    entry.  Faster than bfd_getl32 et al, because we let the compiler
9569    know the value is aligned.  */
9570 
9571 static bfd_vma
ext32l_r_offset(const void * p)9572 ext32l_r_offset (const void *p)
9573 {
9574   union aligned32
9575   {
9576     uint32_t v;
9577     unsigned char c[4];
9578   };
9579   const union aligned32 *a
9580     = (const union aligned32 *) &((const Elf32_External_Rel *) p)->r_offset;
9581 
9582   uint32_t aval = (  (uint32_t) a->c[0]
9583                        | (uint32_t) a->c[1] << 8
9584                        | (uint32_t) a->c[2] << 16
9585                        | (uint32_t) a->c[3] << 24);
9586   return aval;
9587 }
9588 
9589 static bfd_vma
ext32b_r_offset(const void * p)9590 ext32b_r_offset (const void *p)
9591 {
9592   union aligned32
9593   {
9594     uint32_t v;
9595     unsigned char c[4];
9596   };
9597   const union aligned32 *a
9598     = (const union aligned32 *) &((const Elf32_External_Rel *) p)->r_offset;
9599 
9600   uint32_t aval = (  (uint32_t) a->c[0] << 24
9601                        | (uint32_t) a->c[1] << 16
9602                        | (uint32_t) a->c[2] << 8
9603                        | (uint32_t) a->c[3]);
9604   return aval;
9605 }
9606 
9607 static bfd_vma
ext64l_r_offset(const void * p)9608 ext64l_r_offset (const void *p)
9609 {
9610   union aligned64
9611   {
9612     uint64_t v;
9613     unsigned char c[8];
9614   };
9615   const union aligned64 *a
9616     = (const union aligned64 *) &((const Elf64_External_Rel *) p)->r_offset;
9617 
9618   uint64_t aval = (  (uint64_t) a->c[0]
9619                        | (uint64_t) a->c[1] << 8
9620                        | (uint64_t) a->c[2] << 16
9621                        | (uint64_t) a->c[3] << 24
9622                        | (uint64_t) a->c[4] << 32
9623                        | (uint64_t) a->c[5] << 40
9624                        | (uint64_t) a->c[6] << 48
9625                        | (uint64_t) a->c[7] << 56);
9626   return aval;
9627 }
9628 
9629 static bfd_vma
ext64b_r_offset(const void * p)9630 ext64b_r_offset (const void *p)
9631 {
9632   union aligned64
9633   {
9634     uint64_t v;
9635     unsigned char c[8];
9636   };
9637   const union aligned64 *a
9638     = (const union aligned64 *) &((const Elf64_External_Rel *) p)->r_offset;
9639 
9640   uint64_t aval = (  (uint64_t) a->c[0] << 56
9641                        | (uint64_t) a->c[1] << 48
9642                        | (uint64_t) a->c[2] << 40
9643                        | (uint64_t) a->c[3] << 32
9644                        | (uint64_t) a->c[4] << 24
9645                        | (uint64_t) a->c[5] << 16
9646                        | (uint64_t) a->c[6] << 8
9647                        | (uint64_t) a->c[7]);
9648   return aval;
9649 }
9650 
9651 /* When performing a relocatable link, the input relocations are
9652    preserved.  But, if they reference global symbols, the indices
9653    referenced must be updated.  Update all the relocations found in
9654    RELDATA.  */
9655 
9656 static bool
elf_link_adjust_relocs(bfd * abfd,asection * sec,struct bfd_elf_section_reloc_data * reldata,bool sort,struct bfd_link_info * info)9657 elf_link_adjust_relocs (bfd *abfd,
9658                               asection *sec,
9659                               struct bfd_elf_section_reloc_data *reldata,
9660                               bool sort,
9661                               struct bfd_link_info *info)
9662 {
9663   unsigned int i;
9664   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
9665   bfd_byte *erela;
9666   void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
9667   void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
9668   bfd_vma r_type_mask;
9669   int r_sym_shift;
9670   unsigned int count = reldata->count;
9671   struct elf_link_hash_entry **rel_hash = reldata->hashes;
9672 
9673   if (reldata->hdr->sh_entsize == bed->s->sizeof_rel)
9674     {
9675       swap_in = bed->s->swap_reloc_in;
9676       swap_out = bed->s->swap_reloc_out;
9677     }
9678   else if (reldata->hdr->sh_entsize == bed->s->sizeof_rela)
9679     {
9680       swap_in = bed->s->swap_reloca_in;
9681       swap_out = bed->s->swap_reloca_out;
9682     }
9683   else
9684     abort ();
9685 
9686   if (bed->s->int_rels_per_ext_rel > MAX_INT_RELS_PER_EXT_REL)
9687     abort ();
9688 
9689   if (bed->s->arch_size == 32)
9690     {
9691       r_type_mask = 0xff;
9692       r_sym_shift = 8;
9693     }
9694   else
9695     {
9696       r_type_mask = 0xffffffff;
9697       r_sym_shift = 32;
9698     }
9699 
9700   erela = reldata->hdr->contents;
9701   for (i = 0; i < count; i++, rel_hash++, erela += reldata->hdr->sh_entsize)
9702     {
9703       Elf_Internal_Rela irela[MAX_INT_RELS_PER_EXT_REL];
9704       unsigned int j;
9705 
9706       if (*rel_hash == NULL)
9707           continue;
9708 
9709       if ((*rel_hash)->indx == -2
9710             && info->gc_sections
9711             && ! info->gc_keep_exported)
9712           {
9713             /* PR 21524: Let the user know if a symbol was removed by garbage collection.  */
9714             _bfd_error_handler (_("%pB:%pA: error: relocation references symbol %s which was removed by garbage collection"),
9715                                     abfd, sec,
9716                                     (*rel_hash)->root.root.string);
9717             _bfd_error_handler (_("%pB:%pA: error: try relinking with --gc-keep-exported enabled"),
9718                                     abfd, sec);
9719             bfd_set_error (bfd_error_invalid_operation);
9720             return false;
9721           }
9722       BFD_ASSERT ((*rel_hash)->indx >= 0);
9723 
9724       (*swap_in) (abfd, erela, irela);
9725       for (j = 0; j < bed->s->int_rels_per_ext_rel; j++)
9726           irela[j].r_info = ((bfd_vma) (*rel_hash)->indx << r_sym_shift
9727                                  | (irela[j].r_info & r_type_mask));
9728       (*swap_out) (abfd, irela, erela);
9729     }
9730 
9731   if (bed->elf_backend_update_relocs)
9732     (*bed->elf_backend_update_relocs) (sec, reldata);
9733 
9734   if (sort && count != 0)
9735     {
9736       bfd_vma (*ext_r_off) (const void *);
9737       bfd_vma r_off;
9738       size_t elt_size;
9739       bfd_byte *base, *end, *p, *loc;
9740       bfd_byte *buf = NULL;
9741 
9742       if (bed->s->arch_size == 32)
9743           {
9744             if (abfd->xvec->header_byteorder == BFD_ENDIAN_LITTLE)
9745               ext_r_off = ext32l_r_offset;
9746             else if (abfd->xvec->header_byteorder == BFD_ENDIAN_BIG)
9747               ext_r_off = ext32b_r_offset;
9748             else
9749               abort ();
9750           }
9751       else
9752           {
9753             if (abfd->xvec->header_byteorder == BFD_ENDIAN_LITTLE)
9754               ext_r_off = ext64l_r_offset;
9755             else if (abfd->xvec->header_byteorder == BFD_ENDIAN_BIG)
9756               ext_r_off = ext64b_r_offset;
9757             else
9758               abort ();
9759           }
9760 
9761       /*  Must use a stable sort here.  A modified insertion sort,
9762             since the relocs are mostly sorted already.  */
9763       elt_size = reldata->hdr->sh_entsize;
9764       base = reldata->hdr->contents;
9765       end = base + count * elt_size;
9766       if (elt_size > sizeof (Elf64_External_Rela))
9767           abort ();
9768 
9769       /* Ensure the first element is lowest.  This acts as a sentinel,
9770            speeding the main loop below.  */
9771       r_off = (*ext_r_off) (base);
9772       for (p = loc = base; (p += elt_size) < end; )
9773           {
9774             bfd_vma r_off2 = (*ext_r_off) (p);
9775             if (r_off > r_off2)
9776               {
9777                 r_off = r_off2;
9778                 loc = p;
9779               }
9780           }
9781       if (loc != base)
9782           {
9783             /* Don't just swap *base and *loc as that changes the order
9784                of the original base[0] and base[1] if they happen to
9785                have the same r_offset.  */
9786             bfd_byte onebuf[sizeof (Elf64_External_Rela)];
9787             memcpy (onebuf, loc, elt_size);
9788             memmove (base + elt_size, base, loc - base);
9789             memcpy (base, onebuf, elt_size);
9790           }
9791 
9792       for (p = base + elt_size; (p += elt_size) < end; )
9793           {
9794             /* base to p is sorted, *p is next to insert.  */
9795             r_off = (*ext_r_off) (p);
9796             /* Search the sorted region for location to insert.  */
9797             loc = p - elt_size;
9798             while (r_off < (*ext_r_off) (loc))
9799               loc -= elt_size;
9800             loc += elt_size;
9801             if (loc != p)
9802               {
9803                 /* Chances are there is a run of relocs to insert here,
9804                      from one of more input files.  Files are not always
9805                      linked in order due to the way elf_link_input_bfd is
9806                      called.  See pr17666.  */
9807                 size_t sortlen = p - loc;
9808                 bfd_vma r_off2 = (*ext_r_off) (loc);
9809                 size_t runlen = elt_size;
9810                 bfd_vma r_off_runend = r_off;
9811                 bfd_vma r_off_runend_next;
9812                 size_t buf_size = 96 * 1024;
9813                 while (p + runlen < end
9814                          && (sortlen <= buf_size
9815                                || runlen + elt_size <= buf_size)
9816                          /* run must not break the ordering of base..loc+1 */
9817                          && r_off2 > (r_off_runend_next = (*ext_r_off) (p + runlen))
9818                          /* run must be already sorted */
9819                          && r_off_runend_next >= r_off_runend)
9820                     {
9821                       runlen += elt_size;
9822                       r_off_runend = r_off_runend_next;
9823                     }
9824                 if (buf == NULL)
9825                     {
9826                       buf = bfd_malloc (buf_size);
9827                       if (buf == NULL)
9828                         return false;
9829                     }
9830                 if (runlen < sortlen)
9831                     {
9832                       memcpy (buf, p, runlen);
9833                       memmove (loc + runlen, loc, sortlen);
9834                       memcpy (loc, buf, runlen);
9835                     }
9836                 else
9837                     {
9838                       memcpy (buf, loc, sortlen);
9839                       memmove (loc, p, runlen);
9840                       memcpy (loc + runlen, buf, sortlen);
9841                     }
9842                 p += runlen - elt_size;
9843               }
9844           }
9845       /* Hashes are no longer valid.  */
9846       free (reldata->hashes);
9847       reldata->hashes = NULL;
9848       free (buf);
9849     }
9850   return true;
9851 }
9852 
9853 struct elf_link_sort_rela
9854 {
9855   union {
9856     bfd_vma offset;
9857     bfd_vma sym_mask;
9858   } u;
9859   enum elf_reloc_type_class type;
9860   /* We use this as an array of size int_rels_per_ext_rel.  */
9861   Elf_Internal_Rela rela[1];
9862 };
9863 
9864 /* qsort stability here and for cmp2 is only an issue if multiple
9865    dynamic relocations are emitted at the same address.  But targets
9866    that apply a series of dynamic relocations each operating on the
9867    result of the prior relocation can't use -z combreloc as
9868    implemented anyway.  Such schemes tend to be broken by sorting on
9869    symbol index.  That leaves dynamic NONE relocs as the only other
9870    case where ld might emit multiple relocs at the same address, and
9871    those are only emitted due to target bugs.  */
9872 
9873 static int
elf_link_sort_cmp1(const void * A,const void * B)9874 elf_link_sort_cmp1 (const void *A, const void *B)
9875 {
9876   const struct elf_link_sort_rela *a = (const struct elf_link_sort_rela *) A;
9877   const struct elf_link_sort_rela *b = (const struct elf_link_sort_rela *) B;
9878   int relativea, relativeb;
9879 
9880   relativea = a->type == reloc_class_relative;
9881   relativeb = b->type == reloc_class_relative;
9882 
9883   if (relativea < relativeb)
9884     return 1;
9885   if (relativea > relativeb)
9886     return -1;
9887   if ((a->rela->r_info & a->u.sym_mask) < (b->rela->r_info & b->u.sym_mask))
9888     return -1;
9889   if ((a->rela->r_info & a->u.sym_mask) > (b->rela->r_info & b->u.sym_mask))
9890     return 1;
9891   if (a->rela->r_offset < b->rela->r_offset)
9892     return -1;
9893   if (a->rela->r_offset > b->rela->r_offset)
9894     return 1;
9895   return 0;
9896 }
9897 
9898 static int
elf_link_sort_cmp2(const void * A,const void * B)9899 elf_link_sort_cmp2 (const void *A, const void *B)
9900 {
9901   const struct elf_link_sort_rela *a = (const struct elf_link_sort_rela *) A;
9902   const struct elf_link_sort_rela *b = (const struct elf_link_sort_rela *) B;
9903 
9904   if (a->type < b->type)
9905     return -1;
9906   if (a->type > b->type)
9907     return 1;
9908   if (a->u.offset < b->u.offset)
9909     return -1;
9910   if (a->u.offset > b->u.offset)
9911     return 1;
9912   if (a->rela->r_offset < b->rela->r_offset)
9913     return -1;
9914   if (a->rela->r_offset > b->rela->r_offset)
9915     return 1;
9916   return 0;
9917 }
9918 
9919 static size_t
elf_link_sort_relocs(bfd * abfd,struct bfd_link_info * info,asection ** psec)9920 elf_link_sort_relocs (bfd *abfd, struct bfd_link_info *info, asection **psec)
9921 {
9922   asection *dynamic_relocs;
9923   asection *rela_dyn;
9924   asection *rel_dyn;
9925   bfd_size_type count, size;
9926   size_t i, ret, sort_elt, ext_size;
9927   bfd_byte *sort, *s_non_relative, *p;
9928   struct elf_link_sort_rela *sq;
9929   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
9930   int i2e = bed->s->int_rels_per_ext_rel;
9931   unsigned int opb = bfd_octets_per_byte (abfd, NULL);
9932   void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
9933   void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
9934   struct bfd_link_order *lo;
9935   bfd_vma r_sym_mask;
9936   bool use_rela;
9937 
9938   /* Find a dynamic reloc section.  */
9939   rela_dyn = bfd_get_section_by_name (abfd, ".rela.dyn");
9940   rel_dyn  = bfd_get_section_by_name (abfd, ".rel.dyn");
9941   if (rela_dyn != NULL && rela_dyn->size > 0
9942       && rel_dyn != NULL && rel_dyn->size > 0)
9943     {
9944       bool use_rela_initialised = false;
9945 
9946       /* This is just here to stop gcc from complaining.
9947            Its initialization checking code is not perfect.  */
9948       use_rela = true;
9949 
9950       /* Both sections are present.  Examine the sizes
9951            of the indirect sections to help us choose.  */
9952       for (lo = rela_dyn->map_head.link_order; lo != NULL; lo = lo->next)
9953           if (lo->type == bfd_indirect_link_order)
9954             {
9955               asection *o = lo->u.indirect.section;
9956 
9957               if ((o->size % bed->s->sizeof_rela) == 0)
9958                 {
9959                     if ((o->size % bed->s->sizeof_rel) == 0)
9960                       /* Section size is divisible by both rel and rela sizes.
9961                          It is of no help to us.  */
9962                       ;
9963                     else
9964                       {
9965                         /* Section size is only divisible by rela.  */
9966                         if (use_rela_initialised && !use_rela)
9967                           {
9968                               _bfd_error_handler (_("%pB: unable to sort relocs - "
9969                                                         "they are in more than one size"),
9970                                                       abfd);
9971                               bfd_set_error (bfd_error_invalid_operation);
9972                               return 0;
9973                           }
9974                         else
9975                           {
9976                               use_rela = true;
9977                               use_rela_initialised = true;
9978                           }
9979                       }
9980                 }
9981               else if ((o->size % bed->s->sizeof_rel) == 0)
9982                 {
9983                     /* Section size is only divisible by rel.  */
9984                     if (use_rela_initialised && use_rela)
9985                       {
9986                         _bfd_error_handler (_("%pB: unable to sort relocs - "
9987                                                     "they are in more than one size"),
9988                                                   abfd);
9989                         bfd_set_error (bfd_error_invalid_operation);
9990                         return 0;
9991                       }
9992                     else
9993                       {
9994                         use_rela = false;
9995                         use_rela_initialised = true;
9996                       }
9997                 }
9998               else
9999                 {
10000                     /* The section size is not divisible by either -
10001                        something is wrong.  */
10002                     _bfd_error_handler (_("%pB: unable to sort relocs - "
10003                                               "they are of an unknown size"), abfd);
10004                     bfd_set_error (bfd_error_invalid_operation);
10005                     return 0;
10006                 }
10007             }
10008 
10009       for (lo = rel_dyn->map_head.link_order; lo != NULL; lo = lo->next)
10010           if (lo->type == bfd_indirect_link_order)
10011             {
10012               asection *o = lo->u.indirect.section;
10013 
10014               if ((o->size % bed->s->sizeof_rela) == 0)
10015                 {
10016                     if ((o->size % bed->s->sizeof_rel) == 0)
10017                       /* Section size is divisible by both rel and rela sizes.
10018                          It is of no help to us.  */
10019                       ;
10020                     else
10021                       {
10022                         /* Section size is only divisible by rela.  */
10023                         if (use_rela_initialised && !use_rela)
10024                           {
10025                               _bfd_error_handler (_("%pB: unable to sort relocs - "
10026                                                         "they are in more than one size"),
10027                                                       abfd);
10028                               bfd_set_error (bfd_error_invalid_operation);
10029                               return 0;
10030                           }
10031                         else
10032                           {
10033                               use_rela = true;
10034                               use_rela_initialised = true;
10035                           }
10036                       }
10037                 }
10038               else if ((o->size % bed->s->sizeof_rel) == 0)
10039                 {
10040                     /* Section size is only divisible by rel.  */
10041                     if (use_rela_initialised && use_rela)
10042                       {
10043                         _bfd_error_handler (_("%pB: unable to sort relocs - "
10044                                                     "they are in more than one size"),
10045                                                   abfd);
10046                         bfd_set_error (bfd_error_invalid_operation);
10047                         return 0;
10048                       }
10049                     else
10050                       {
10051                         use_rela = false;
10052                         use_rela_initialised = true;
10053                       }
10054                 }
10055               else
10056                 {
10057                     /* The section size is not divisible by either -
10058                        something is wrong.  */
10059                     _bfd_error_handler (_("%pB: unable to sort relocs - "
10060                                               "they are of an unknown size"), abfd);
10061                     bfd_set_error (bfd_error_invalid_operation);
10062                     return 0;
10063                 }
10064             }
10065 
10066       if (! use_rela_initialised)
10067           /* Make a guess.  */
10068           use_rela = true;
10069     }
10070   else if (rela_dyn != NULL && rela_dyn->size > 0)
10071     use_rela = true;
10072   else if (rel_dyn != NULL && rel_dyn->size > 0)
10073     use_rela = false;
10074   else
10075     return 0;
10076 
10077   if (use_rela)
10078     {
10079       dynamic_relocs = rela_dyn;
10080       ext_size = bed->s->sizeof_rela;
10081       swap_in = bed->s->swap_reloca_in;
10082       swap_out = bed->s->swap_reloca_out;
10083     }
10084   else
10085     {
10086       dynamic_relocs = rel_dyn;
10087       ext_size = bed->s->sizeof_rel;
10088       swap_in = bed->s->swap_reloc_in;
10089       swap_out = bed->s->swap_reloc_out;
10090     }
10091 
10092   size = 0;
10093   for (lo = dynamic_relocs->map_head.link_order; lo != NULL; lo = lo->next)
10094     if (lo->type == bfd_indirect_link_order)
10095       size += lo->u.indirect.section->size;
10096 
10097   if (size != dynamic_relocs->size)
10098     return 0;
10099 
10100   sort_elt = (sizeof (struct elf_link_sort_rela)
10101                 + (i2e - 1) * sizeof (Elf_Internal_Rela));
10102 
10103   count = dynamic_relocs->size / ext_size;
10104   if (count == 0)
10105     return 0;
10106   sort = (bfd_byte *) bfd_zmalloc (sort_elt * count);
10107 
10108   if (sort == NULL)
10109     {
10110       (*info->callbacks->warning)
10111           (info, _("not enough memory to sort relocations"), 0, abfd, 0, 0);
10112       return 0;
10113     }
10114 
10115   if (bed->s->arch_size == 32)
10116     r_sym_mask = ~(bfd_vma) 0xff;
10117   else
10118     r_sym_mask = ~(bfd_vma) 0xffffffff;
10119 
10120   for (lo = dynamic_relocs->map_head.link_order; lo != NULL; lo = lo->next)
10121     if (lo->type == bfd_indirect_link_order)
10122       {
10123           bfd_byte *erel, *erelend;
10124           asection *o = lo->u.indirect.section;
10125 
10126           if (o->contents == NULL && o->size != 0)
10127             {
10128               /* This is a reloc section that is being handled as a normal
10129                  section.  See bfd_section_from_shdr.  We can't combine
10130                  relocs in this case.  */
10131               free (sort);
10132               return 0;
10133             }
10134           erel = o->contents;
10135           erelend = o->contents + o->size;
10136           p = sort + o->output_offset * opb / ext_size * sort_elt;
10137 
10138           while (erel < erelend)
10139             {
10140               struct elf_link_sort_rela *s = (struct elf_link_sort_rela *) p;
10141 
10142               (*swap_in) (abfd, erel, s->rela);
10143               s->type = (*bed->elf_backend_reloc_type_class) (info, o, s->rela);
10144               s->u.sym_mask = r_sym_mask;
10145               p += sort_elt;
10146               erel += ext_size;
10147             }
10148       }
10149 
10150   qsort (sort, count, sort_elt, elf_link_sort_cmp1);
10151 
10152   for (i = 0, p = sort; i < count; i++, p += sort_elt)
10153     {
10154       struct elf_link_sort_rela *s = (struct elf_link_sort_rela *) p;
10155       if (s->type != reloc_class_relative)
10156           break;
10157     }
10158   ret = i;
10159   s_non_relative = p;
10160 
10161   sq = (struct elf_link_sort_rela *) s_non_relative;
10162   for (; i < count; i++, p += sort_elt)
10163     {
10164       struct elf_link_sort_rela *sp = (struct elf_link_sort_rela *) p;
10165       if (((sp->rela->r_info ^ sq->rela->r_info) & r_sym_mask) != 0)
10166           sq = sp;
10167       sp->u.offset = sq->rela->r_offset;
10168     }
10169 
10170   qsort (s_non_relative, count - ret, sort_elt, elf_link_sort_cmp2);
10171 
10172   struct elf_link_hash_table *htab = elf_hash_table (info);
10173   if (htab->srelplt && htab->srelplt->output_section == dynamic_relocs)
10174     {
10175       /* We have plt relocs in .rela.dyn.  */
10176       sq = (struct elf_link_sort_rela *) sort;
10177       for (i = 0; i < count; i++)
10178           if (sq[count - i - 1].type != reloc_class_plt)
10179             break;
10180       if (i != 0 && htab->srelplt->size == i * ext_size)
10181           {
10182             struct bfd_link_order **plo;
10183             /* Put srelplt link_order last.  This is so the output_offset
10184                set in the next loop is correct for DT_JMPREL.  */
10185             for (plo = &dynamic_relocs->map_head.link_order; *plo != NULL; )
10186               if ((*plo)->type == bfd_indirect_link_order
10187                     && (*plo)->u.indirect.section == htab->srelplt)
10188                 {
10189                     lo = *plo;
10190                     *plo = lo->next;
10191                 }
10192               else
10193                 plo = &(*plo)->next;
10194             *plo = lo;
10195             lo->next = NULL;
10196             dynamic_relocs->map_tail.link_order = lo;
10197           }
10198     }
10199 
10200   p = sort;
10201   for (lo = dynamic_relocs->map_head.link_order; lo != NULL; lo = lo->next)
10202     if (lo->type == bfd_indirect_link_order)
10203       {
10204           bfd_byte *erel, *erelend;
10205           asection *o = lo->u.indirect.section;
10206 
10207           erel = o->contents;
10208           erelend = o->contents + o->size;
10209           o->output_offset = (p - sort) / sort_elt * ext_size / opb;
10210           while (erel < erelend)
10211             {
10212               struct elf_link_sort_rela *s = (struct elf_link_sort_rela *) p;
10213               (*swap_out) (abfd, s->rela, erel);
10214               p += sort_elt;
10215               erel += ext_size;
10216             }
10217       }
10218 
10219   free (sort);
10220   *psec = dynamic_relocs;
10221   return ret;
10222 }
10223 
10224 /* Add a symbol to the output symbol string table.  */
10225 
10226 static int
elf_link_output_symstrtab(void * finf,const char * name,Elf_Internal_Sym * elfsym,asection * input_sec,struct elf_link_hash_entry * h)10227 elf_link_output_symstrtab (void *finf,
10228                                  const char *name,
10229                                  Elf_Internal_Sym *elfsym,
10230                                  asection *input_sec,
10231                                  struct elf_link_hash_entry *h)
10232 {
10233   struct elf_final_link_info *flinfo = finf;
10234   int (*output_symbol_hook)
10235     (struct bfd_link_info *, const char *, Elf_Internal_Sym *, asection *,
10236      struct elf_link_hash_entry *);
10237   struct elf_link_hash_table *hash_table;
10238   const struct elf_backend_data *bed;
10239   bfd_size_type strtabsize;
10240 
10241   BFD_ASSERT (elf_onesymtab (flinfo->output_bfd));
10242 
10243   bed = get_elf_backend_data (flinfo->output_bfd);
10244   output_symbol_hook = bed->elf_backend_link_output_symbol_hook;
10245   if (output_symbol_hook != NULL)
10246     {
10247       int ret = (*output_symbol_hook) (flinfo->info, name, elfsym, input_sec, h);
10248       if (ret != 1)
10249           return ret;
10250     }
10251 
10252   if (ELF_ST_TYPE (elfsym->st_info) == STT_GNU_IFUNC)
10253     elf_tdata (flinfo->output_bfd)->has_gnu_osabi |= elf_gnu_osabi_ifunc;
10254   if (ELF_ST_BIND (elfsym->st_info) == STB_GNU_UNIQUE)
10255     elf_tdata (flinfo->output_bfd)->has_gnu_osabi |= elf_gnu_osabi_unique;
10256 
10257   if (name == NULL || *name == '\0')
10258     elfsym->st_name = (unsigned long) -1;
10259   else
10260     {
10261       /* Call _bfd_elf_strtab_offset after _bfd_elf_strtab_finalize
10262            to get the final offset for st_name.  */
10263       char *versioned_name = (char *) name;
10264       if (h != NULL)
10265           {
10266             if (h->versioned == versioned && h->def_dynamic)
10267               {
10268                 /* Keep only one '@' for versioned symbols defined in
10269                    shared objects.  */
10270                 char *version = strrchr (name, ELF_VER_CHR);
10271                 char *base_end = strchr (name, ELF_VER_CHR);
10272                 if (version != base_end)
10273                     {
10274                       size_t base_len;
10275                       size_t len = strlen (name);
10276                       versioned_name = bfd_alloc (flinfo->output_bfd, len);
10277                       if (versioned_name == NULL)
10278                         return 0;
10279                       base_len = base_end - name;
10280                       memcpy (versioned_name, name, base_len);
10281                       memcpy (versioned_name + base_len, version,
10282                                 len - base_len);
10283                     }
10284               }
10285           }
10286       else if (flinfo->info->unique_symbol
10287                  && ELF_ST_BIND (elfsym->st_info) == STB_LOCAL)
10288           {
10289             struct local_hash_entry *lh;
10290             size_t count_len;
10291             size_t base_len;
10292             char buf[30];
10293             switch (ELF_ST_TYPE (elfsym->st_info))
10294               {
10295               case STT_FILE:
10296               case STT_SECTION:
10297                 break;
10298               default:
10299                 lh = (struct local_hash_entry *) bfd_hash_lookup
10300                          (&flinfo->local_hash_table, name, true, false);
10301                 if (lh == NULL)
10302                     return 0;
10303                 /* Always append ".COUNT" to local symbols to avoid
10304                      potential conflicts with local symbol "XXX.COUNT".  */
10305                 sprintf (buf, "%lx", lh->count);
10306                 base_len = lh->size;
10307                 if (!base_len)
10308                     {
10309                       base_len = strlen (name);
10310                       lh->size = base_len;
10311                     }
10312                 count_len = strlen (buf);
10313                 versioned_name = bfd_alloc (flinfo->output_bfd,
10314                                                     base_len + count_len + 2);
10315                 if (versioned_name == NULL)
10316                     return 0;
10317                 memcpy (versioned_name, name, base_len);
10318                 versioned_name[base_len] = '.';
10319                 memcpy (versioned_name + base_len + 1, buf,
10320                           count_len + 1);
10321                 lh->count++;
10322                 break;
10323               }
10324           }
10325       elfsym->st_name
10326           = (unsigned long) _bfd_elf_strtab_add (flinfo->symstrtab,
10327                                                          versioned_name, false);
10328       if (elfsym->st_name == (unsigned long) -1)
10329           return 0;
10330     }
10331 
10332   hash_table = elf_hash_table (flinfo->info);
10333   strtabsize = hash_table->strtabsize;
10334   if (strtabsize <= flinfo->output_bfd->symcount)
10335     {
10336       strtabsize += strtabsize;
10337       hash_table->strtabsize = strtabsize;
10338       strtabsize *= sizeof (*hash_table->strtab);
10339       hash_table->strtab
10340           = (struct elf_sym_strtab *) bfd_realloc (hash_table->strtab,
10341                                                              strtabsize);
10342       if (hash_table->strtab == NULL)
10343           return 0;
10344     }
10345   hash_table->strtab[flinfo->output_bfd->symcount].sym = *elfsym;
10346   hash_table->strtab[flinfo->output_bfd->symcount].dest_index
10347     = flinfo->output_bfd->symcount;
10348   flinfo->output_bfd->symcount += 1;
10349 
10350   return 1;
10351 }
10352 
10353 /* Swap symbols out to the symbol table and flush the output symbols to
10354    the file.  */
10355 
10356 static bool
elf_link_swap_symbols_out(struct elf_final_link_info * flinfo)10357 elf_link_swap_symbols_out (struct elf_final_link_info *flinfo)
10358 {
10359   struct elf_link_hash_table *hash_table = elf_hash_table (flinfo->info);
10360   size_t amt;
10361   size_t i;
10362   const struct elf_backend_data *bed;
10363   bfd_byte *symbuf;
10364   Elf_Internal_Shdr *hdr;
10365   file_ptr pos;
10366   bool ret;
10367 
10368   if (flinfo->output_bfd->symcount == 0)
10369     return true;
10370 
10371   BFD_ASSERT (elf_onesymtab (flinfo->output_bfd));
10372 
10373   bed = get_elf_backend_data (flinfo->output_bfd);
10374 
10375   amt = bed->s->sizeof_sym * flinfo->output_bfd->symcount;
10376   symbuf = (bfd_byte *) bfd_malloc (amt);
10377   if (symbuf == NULL)
10378     return false;
10379 
10380   if (flinfo->symshndxbuf)
10381     {
10382       amt = sizeof (Elf_External_Sym_Shndx);
10383       amt *= bfd_get_symcount (flinfo->output_bfd);
10384       flinfo->symshndxbuf = (Elf_External_Sym_Shndx *) bfd_zmalloc (amt);
10385       if (flinfo->symshndxbuf == NULL)
10386           {
10387             free (symbuf);
10388             return false;
10389           }
10390     }
10391 
10392   /* Now swap out the symbols.  */
10393   for (i = 0; i < flinfo->output_bfd->symcount; i++)
10394     {
10395       struct elf_sym_strtab *elfsym = &hash_table->strtab[i];
10396       if (elfsym->sym.st_name == (unsigned long) -1)
10397           elfsym->sym.st_name = 0;
10398       else
10399           elfsym->sym.st_name
10400             = (unsigned long) _bfd_elf_strtab_offset (flinfo->symstrtab,
10401                                                                 elfsym->sym.st_name);
10402 
10403       /* Inform the linker of the addition of this symbol.  */
10404 
10405       if (flinfo->info->callbacks->ctf_new_symbol)
10406           flinfo->info->callbacks->ctf_new_symbol (elfsym->dest_index,
10407                                                              &elfsym->sym);
10408 
10409       bed->s->swap_symbol_out (flinfo->output_bfd, &elfsym->sym,
10410                                      ((bfd_byte *) symbuf
10411                                         + (elfsym->dest_index
10412                                            * bed->s->sizeof_sym)),
10413                                      NPTR_ADD (flinfo->symshndxbuf,
10414                                                    elfsym->dest_index));
10415     }
10416 
10417   hdr = &elf_tdata (flinfo->output_bfd)->symtab_hdr;
10418   pos = hdr->sh_offset + hdr->sh_size;
10419   amt = bed->s->sizeof_sym * flinfo->output_bfd->symcount;
10420   if (bfd_seek (flinfo->output_bfd, pos, SEEK_SET) == 0
10421       && bfd_write (symbuf, amt, flinfo->output_bfd) == amt)
10422     {
10423       hdr->sh_size += amt;
10424       ret = true;
10425     }
10426   else
10427     ret = false;
10428 
10429   free (symbuf);
10430 
10431   free (hash_table->strtab);
10432   hash_table->strtab = NULL;
10433 
10434   return ret;
10435 }
10436 
10437 /* Return TRUE if the dynamic symbol SYM in ABFD is supported.  */
10438 
10439 static bool
check_dynsym(bfd * abfd,Elf_Internal_Sym * sym)10440 check_dynsym (bfd *abfd, Elf_Internal_Sym *sym)
10441 {
10442   if (sym->st_shndx >= (SHN_LORESERVE & 0xffff)
10443       && sym->st_shndx < SHN_LORESERVE)
10444     {
10445       /* The gABI doesn't support dynamic symbols in output sections
10446            beyond 64k.  */
10447       _bfd_error_handler
10448           /* xgettext:c-format */
10449           (_("%pB: too many sections: %d (>= %d)"),
10450            abfd, bfd_count_sections (abfd), SHN_LORESERVE & 0xffff);
10451       bfd_set_error (bfd_error_nonrepresentable_section);
10452       return false;
10453     }
10454   return true;
10455 }
10456 
10457 /* For DSOs loaded in via a DT_NEEDED entry, emulate ld.so in
10458    allowing an unsatisfied unversioned symbol in the DSO to match a
10459    versioned symbol that would normally require an explicit version.
10460    We also handle the case that a DSO references a hidden symbol
10461    which may be satisfied by a versioned symbol in another DSO.  */
10462 
10463 static bool
elf_link_check_versioned_symbol(struct bfd_link_info * info,const struct elf_backend_data * bed,struct elf_link_hash_entry * h)10464 elf_link_check_versioned_symbol (struct bfd_link_info *info,
10465                                          const struct elf_backend_data *bed,
10466                                          struct elf_link_hash_entry *h)
10467 {
10468   bfd *abfd;
10469   struct elf_link_loaded_list *loaded;
10470 
10471   if (!is_elf_hash_table (info->hash))
10472     return false;
10473 
10474   /* Check indirect symbol.  */
10475   while (h->root.type == bfd_link_hash_indirect)
10476     h = (struct elf_link_hash_entry *) h->root.u.i.link;
10477 
10478   switch (h->root.type)
10479     {
10480     default:
10481       abfd = NULL;
10482       break;
10483 
10484     case bfd_link_hash_undefined:
10485     case bfd_link_hash_undefweak:
10486       abfd = h->root.u.undef.abfd;
10487       if (abfd == NULL
10488             || (abfd->flags & DYNAMIC) == 0
10489             || (elf_dyn_lib_class (abfd) & DYN_DT_NEEDED) == 0)
10490           return false;
10491       break;
10492 
10493     case bfd_link_hash_defined:
10494     case bfd_link_hash_defweak:
10495       abfd = h->root.u.def.section->owner;
10496       break;
10497 
10498     case bfd_link_hash_common:
10499       abfd = h->root.u.c.p->section->owner;
10500       break;
10501     }
10502   BFD_ASSERT (abfd != NULL);
10503 
10504   for (loaded = elf_hash_table (info)->dyn_loaded;
10505        loaded != NULL;
10506        loaded = loaded->next)
10507     {
10508       bfd *input;
10509       Elf_Internal_Shdr *hdr;
10510       size_t symcount;
10511       size_t extsymcount;
10512       size_t extsymoff;
10513       Elf_Internal_Shdr *versymhdr;
10514       Elf_Internal_Sym *isym;
10515       Elf_Internal_Sym *isymend;
10516       Elf_Internal_Sym *isymbuf;
10517       Elf_External_Versym *ever;
10518       Elf_External_Versym *extversym;
10519 
10520       input = loaded->abfd;
10521 
10522       /* We check each DSO for a possible hidden versioned definition.  */
10523       if (input == abfd
10524             || elf_dynversym (input) == 0)
10525           continue;
10526 
10527       hdr = &elf_tdata (input)->dynsymtab_hdr;
10528 
10529       symcount = hdr->sh_size / bed->s->sizeof_sym;
10530       if (elf_bad_symtab (input))
10531           {
10532             extsymcount = symcount;
10533             extsymoff = 0;
10534           }
10535       else
10536           {
10537             extsymcount = symcount - hdr->sh_info;
10538             extsymoff = hdr->sh_info;
10539           }
10540 
10541       if (extsymcount == 0)
10542           continue;
10543 
10544       isymbuf = bfd_elf_get_elf_syms (input, hdr, extsymcount, extsymoff,
10545                                               NULL, NULL, NULL);
10546       if (isymbuf == NULL)
10547           return false;
10548 
10549       /* Read in any version definitions.  */
10550       versymhdr = &elf_tdata (input)->dynversym_hdr;
10551       if (bfd_seek (input, versymhdr->sh_offset, SEEK_SET) != 0
10552             || (extversym = (Elf_External_Versym *)
10553                 _bfd_malloc_and_read (input, versymhdr->sh_size,
10554                                             versymhdr->sh_size)) == NULL)
10555           {
10556             free (isymbuf);
10557             return false;
10558           }
10559 
10560       ever = extversym + extsymoff;
10561       isymend = isymbuf + extsymcount;
10562       for (isym = isymbuf; isym < isymend; isym++, ever++)
10563           {
10564             const char *name;
10565             Elf_Internal_Versym iver;
10566             unsigned short version_index;
10567 
10568             if (ELF_ST_BIND (isym->st_info) == STB_LOCAL
10569                 || isym->st_shndx == SHN_UNDEF)
10570               continue;
10571 
10572             name = bfd_elf_string_from_elf_section (input,
10573                                                               hdr->sh_link,
10574                                                               isym->st_name);
10575             if (strcmp (name, h->root.root.string) != 0)
10576               continue;
10577 
10578             _bfd_elf_swap_versym_in (input, ever, &iver);
10579 
10580             if ((iver.vs_vers & VERSYM_HIDDEN) == 0
10581                 && !(h->def_regular
10582                        && h->forced_local))
10583               {
10584                 /* If we have a non-hidden versioned sym, then it should
10585                      have provided a definition for the undefined sym unless
10586                      it is defined in a non-shared object and forced local.
10587                  */
10588                 abort ();
10589               }
10590 
10591             version_index = iver.vs_vers & VERSYM_VERSION;
10592             if (version_index == 1 || version_index == 2)
10593               {
10594                 /* This is the base or first version.  We can use it.  */
10595                 free (extversym);
10596                 free (isymbuf);
10597                 return true;
10598               }
10599           }
10600 
10601       free (extversym);
10602       free (isymbuf);
10603     }
10604 
10605   return false;
10606 }
10607 
10608 /* Convert ELF common symbol TYPE.  */
10609 
10610 static int
elf_link_convert_common_type(struct bfd_link_info * info,int type)10611 elf_link_convert_common_type (struct bfd_link_info *info, int type)
10612 {
10613   /* Commom symbol can only appear in relocatable link.  */
10614   if (!bfd_link_relocatable (info))
10615     abort ();
10616   switch (info->elf_stt_common)
10617     {
10618     case unchanged:
10619       break;
10620     case elf_stt_common:
10621       type = STT_COMMON;
10622       break;
10623     case no_elf_stt_common:
10624       type = STT_OBJECT;
10625       break;
10626     }
10627   return type;
10628 }
10629 
10630 /* Add an external symbol to the symbol table.  This is called from
10631    the hash table traversal routine.  When generating a shared object,
10632    we go through the symbol table twice.  The first time we output
10633    anything that might have been forced to local scope in a version
10634    script.  The second time we output the symbols that are still
10635    global symbols.  */
10636 
10637 static bool
elf_link_output_extsym(struct bfd_hash_entry * bh,void * data)10638 elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
10639 {
10640   struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) bh;
10641   struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
10642   struct elf_final_link_info *flinfo = eoinfo->flinfo;
10643   bool strip;
10644   Elf_Internal_Sym sym;
10645   asection *input_sec;
10646   const struct elf_backend_data *bed;
10647   long indx;
10648   int ret;
10649   unsigned int type;
10650 
10651   if (h->root.type == bfd_link_hash_warning)
10652     {
10653       h = (struct elf_link_hash_entry *) h->root.u.i.link;
10654       if (h->root.type == bfd_link_hash_new)
10655           return true;
10656     }
10657 
10658   /* Decide whether to output this symbol in this pass.  */
10659   if (eoinfo->localsyms)
10660     {
10661       if (!h->forced_local)
10662           return true;
10663     }
10664   else
10665     {
10666       if (h->forced_local)
10667           return true;
10668     }
10669 
10670   bed = get_elf_backend_data (flinfo->output_bfd);
10671 
10672   if (h->root.type == bfd_link_hash_undefined)
10673     {
10674       /* If we have an undefined symbol reference here then it must have
10675            come from a shared library that is being linked in.  (Undefined
10676            references in regular files have already been handled unless
10677            they are in unreferenced sections which are removed by garbage
10678            collection).  */
10679       bool ignore_undef = false;
10680 
10681       /* Some symbols may be special in that the fact that they're
10682            undefined can be safely ignored - let backend determine that.  */
10683       if (bed->elf_backend_ignore_undef_symbol)
10684           ignore_undef = bed->elf_backend_ignore_undef_symbol (h);
10685 
10686       /* If we are reporting errors for this situation then do so now.  */
10687       if (!ignore_undef
10688             && h->ref_dynamic_nonweak
10689             && (!h->ref_regular || flinfo->info->gc_sections)
10690             && !elf_link_check_versioned_symbol (flinfo->info, bed, h)
10691             && flinfo->info->unresolved_syms_in_shared_libs != RM_IGNORE)
10692           {
10693             flinfo->info->callbacks->undefined_symbol
10694               (flinfo->info, h->root.root.string,
10695                h->ref_regular ? NULL : h->root.u.undef.abfd, NULL, 0,
10696                flinfo->info->unresolved_syms_in_shared_libs == RM_DIAGNOSE
10697                && !flinfo->info->warn_unresolved_syms);
10698           }
10699 
10700       /* Strip a global symbol defined in a discarded section.  */
10701       if (h->indx == -3)
10702           return true;
10703     }
10704 
10705   /* We should also warn if a forced local symbol is referenced from
10706      shared libraries.  */
10707   if (bfd_link_executable (flinfo->info)
10708       && h->forced_local
10709       && h->ref_dynamic
10710       && h->def_regular
10711       && !h->dynamic_def
10712       && h->ref_dynamic_nonweak
10713       && !elf_link_check_versioned_symbol (flinfo->info, bed, h))
10714     {
10715       bfd *def_bfd;
10716       const char *msg;
10717       struct elf_link_hash_entry *hi = h;
10718 
10719       /* Check indirect symbol.  */
10720       while (hi->root.type == bfd_link_hash_indirect)
10721           hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
10722 
10723       if (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL)
10724           /* xgettext:c-format */
10725           msg = _("%pB: internal symbol `%s' in %pB is referenced by DSO");
10726       else if (ELF_ST_VISIBILITY (h->other) == STV_HIDDEN)
10727           /* xgettext:c-format */
10728           msg = _("%pB: hidden symbol `%s' in %pB is referenced by DSO");
10729       else
10730           /* xgettext:c-format */
10731           msg = _("%pB: local symbol `%s' in %pB is referenced by DSO");
10732       def_bfd = flinfo->output_bfd;
10733       if (hi->root.u.def.section != bfd_abs_section_ptr)
10734           def_bfd = hi->root.u.def.section->owner;
10735       _bfd_error_handler (msg, flinfo->output_bfd,
10736                                 h->root.root.string, def_bfd);
10737       bfd_set_error (bfd_error_bad_value);
10738       eoinfo->failed = true;
10739       return false;
10740     }
10741 
10742   /* We don't want to output symbols that have never been mentioned by
10743      a regular file, or that we have been told to strip.  However, if
10744      h->indx is set to -2, the symbol is used by a reloc and we must
10745      output it.  */
10746   strip = false;
10747   if (h->indx == -2)
10748     ;
10749   else if ((h->def_dynamic
10750               || h->ref_dynamic
10751               || h->root.type == bfd_link_hash_new)
10752              && !h->def_regular
10753              && !h->ref_regular)
10754     strip = true;
10755   else if (flinfo->info->strip == strip_all)
10756     strip = true;
10757   else if (flinfo->info->strip == strip_some
10758              && bfd_hash_lookup (flinfo->info->keep_hash,
10759                                      h->root.root.string, false, false) == NULL)
10760     strip = true;
10761   else if ((h->root.type == bfd_link_hash_defined
10762               || h->root.type == bfd_link_hash_defweak)
10763              && ((flinfo->info->strip_discarded
10764                     && discarded_section (h->root.u.def.section))
10765                  || ((h->root.u.def.section->flags & SEC_LINKER_CREATED) == 0
10766                        && h->root.u.def.section->owner != NULL
10767                        && (h->root.u.def.section->owner->flags & BFD_PLUGIN) != 0)))
10768     strip = true;
10769   else if ((h->root.type == bfd_link_hash_undefined
10770               || h->root.type == bfd_link_hash_undefweak)
10771              && h->root.u.undef.abfd != NULL
10772              && (h->root.u.undef.abfd->flags & BFD_PLUGIN) != 0)
10773     strip = true;
10774 
10775   /* Remember if this symbol should be stripped.  */
10776   bool should_strip = strip;
10777 
10778   /* Strip undefined weak symbols link if they don't have relocation.  */
10779   if (!strip)
10780     strip = !h->has_reloc && h->root.type == bfd_link_hash_undefweak;
10781 
10782   type = h->type;
10783 
10784   /* If we're stripping it, and it's not a dynamic symbol, there's
10785      nothing else to do.   However, if it is a forced local symbol or
10786      an ifunc symbol we need to give the backend finish_dynamic_symbol
10787      function a chance to make it dynamic.  */
10788   if (strip
10789       && h->dynindx == -1
10790       && type != STT_GNU_IFUNC
10791       && !h->forced_local)
10792     return true;
10793 
10794   sym.st_value = 0;
10795   sym.st_size = h->size;
10796   sym.st_other = h->other;
10797   switch (h->root.type)
10798     {
10799     default:
10800     case bfd_link_hash_new:
10801     case bfd_link_hash_warning:
10802       abort ();
10803       return false;
10804 
10805     case bfd_link_hash_undefined:
10806     case bfd_link_hash_undefweak:
10807       input_sec = bfd_und_section_ptr;
10808       sym.st_shndx = SHN_UNDEF;
10809       break;
10810 
10811     case bfd_link_hash_defined:
10812     case bfd_link_hash_defweak:
10813       {
10814           input_sec = h->root.u.def.section;
10815           if (input_sec->output_section != NULL)
10816             {
10817               sym.st_shndx =
10818                 _bfd_elf_section_from_bfd_section (flinfo->output_bfd,
10819                                                              input_sec->output_section);
10820               if (sym.st_shndx == SHN_BAD)
10821                 {
10822                     _bfd_error_handler
10823                       /* xgettext:c-format */
10824                       (_("%pB: could not find output section %pA for input section %pA"),
10825                        flinfo->output_bfd, input_sec->output_section, input_sec);
10826                     bfd_set_error (bfd_error_nonrepresentable_section);
10827                     eoinfo->failed = true;
10828                     return false;
10829                 }
10830 
10831               /* ELF symbols in relocatable files are section relative,
10832                  but in nonrelocatable files they are virtual
10833                  addresses.  */
10834               sym.st_value = h->root.u.def.value + input_sec->output_offset;
10835               if (!bfd_link_relocatable (flinfo->info))
10836                 {
10837                     sym.st_value += input_sec->output_section->vma;
10838                     if (h->type == STT_TLS)
10839                       {
10840                         asection *tls_sec = elf_hash_table (flinfo->info)->tls_sec;
10841                         if (tls_sec != NULL)
10842                           sym.st_value -= tls_sec->vma;
10843                       }
10844                 }
10845             }
10846           else
10847             {
10848               BFD_ASSERT (input_sec->owner == NULL
10849                               || (input_sec->owner->flags & DYNAMIC) != 0);
10850               sym.st_shndx = SHN_UNDEF;
10851               input_sec = bfd_und_section_ptr;
10852             }
10853       }
10854       break;
10855 
10856     case bfd_link_hash_common:
10857       input_sec = h->root.u.c.p->section;
10858       sym.st_shndx = bed->common_section_index (input_sec);
10859       sym.st_value = 1 << h->root.u.c.p->alignment_power;
10860       break;
10861 
10862     case bfd_link_hash_indirect:
10863       /* These symbols are created by symbol versioning.  They point
10864            to the decorated version of the name.  For example, if the
10865            symbol foo@@GNU_1.2 is the default, which should be used when
10866            foo is used with no version, then we add an indirect symbol
10867            foo which points to foo@@GNU_1.2.  We ignore these symbols,
10868            since the indirected symbol is already in the hash table.  */
10869       return true;
10870     }
10871 
10872   if (type == STT_COMMON || type == STT_OBJECT)
10873     switch (h->root.type)
10874       {
10875       case bfd_link_hash_common:
10876           type = elf_link_convert_common_type (flinfo->info, type);
10877           break;
10878       case bfd_link_hash_defined:
10879       case bfd_link_hash_defweak:
10880           if (bed->common_definition (&sym))
10881             type = elf_link_convert_common_type (flinfo->info, type);
10882           else
10883             type = STT_OBJECT;
10884           break;
10885       case bfd_link_hash_undefined:
10886       case bfd_link_hash_undefweak:
10887           break;
10888       default:
10889           abort ();
10890       }
10891 
10892   if (h->forced_local)
10893     {
10894       sym.st_info = ELF_ST_INFO (STB_LOCAL, type);
10895       /* Turn off visibility on local symbol.  */
10896       sym.st_other &= ~ELF_ST_VISIBILITY (-1);
10897     }
10898   /* Set STB_GNU_UNIQUE only if symbol is defined in regular object.  */
10899   else if (h->unique_global && h->def_regular)
10900     sym.st_info = ELF_ST_INFO (STB_GNU_UNIQUE, type);
10901   else if (h->root.type == bfd_link_hash_undefweak
10902              || h->root.type == bfd_link_hash_defweak)
10903     sym.st_info = ELF_ST_INFO (STB_WEAK, type);
10904   else
10905     sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
10906   sym.st_target_internal = h->target_internal;
10907 
10908   /* Give the processor backend a chance to tweak the symbol value,
10909      and also to finish up anything that needs to be done for this
10910      symbol.  FIXME: Not calling elf_backend_finish_dynamic_symbol for
10911      forced local syms when non-shared is due to a historical quirk.
10912      STT_GNU_IFUNC symbol must go through PLT.  */
10913   if ((h->type == STT_GNU_IFUNC
10914        && h->def_regular
10915        && !bfd_link_relocatable (flinfo->info))
10916       || ((h->dynindx != -1
10917              || h->forced_local)
10918             && ((bfd_link_pic (flinfo->info)
10919                  && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
10920                        || h->root.type != bfd_link_hash_undefweak))
10921                 || !h->forced_local)
10922             && elf_hash_table (flinfo->info)->dynamic_sections_created))
10923     {
10924       if (! ((*bed->elf_backend_finish_dynamic_symbol)
10925                (flinfo->output_bfd, flinfo->info, h, &sym)))
10926           {
10927             eoinfo->failed = true;
10928             return false;
10929           }
10930       /* If a symbol is in the dynamic symbol table and isn't a
10931            should-strip symbol, also keep it in the symbol table.  */
10932       if (!should_strip)
10933           strip = false;
10934     }
10935 
10936   /* If we are marking the symbol as undefined, and there are no
10937      non-weak references to this symbol from a regular object, then
10938      mark the symbol as weak undefined; if there are non-weak
10939      references, mark the symbol as strong.  We can't do this earlier,
10940      because it might not be marked as undefined until the
10941      finish_dynamic_symbol routine gets through with it.  */
10942   if (sym.st_shndx == SHN_UNDEF
10943       && h->ref_regular
10944       && (ELF_ST_BIND (sym.st_info) == STB_GLOBAL
10945             || ELF_ST_BIND (sym.st_info) == STB_WEAK))
10946     {
10947       int bindtype;
10948       type = ELF_ST_TYPE (sym.st_info);
10949 
10950       /* Turn an undefined IFUNC symbol into a normal FUNC symbol. */
10951       if (type == STT_GNU_IFUNC)
10952           type = STT_FUNC;
10953 
10954       if (h->ref_regular_nonweak)
10955           bindtype = STB_GLOBAL;
10956       else
10957           bindtype = STB_WEAK;
10958       sym.st_info = ELF_ST_INFO (bindtype, type);
10959     }
10960 
10961   /* If this is a symbol defined in a dynamic library, don't use the
10962      symbol size from the dynamic library.  Relinking an executable
10963      against a new library may introduce gratuitous changes in the
10964      executable's symbols if we keep the size.  */
10965   if (sym.st_shndx == SHN_UNDEF
10966       && !h->def_regular
10967       && h->def_dynamic)
10968     sym.st_size = 0;
10969 
10970   /* If a non-weak symbol with non-default visibility is not defined
10971      locally, it is a fatal error.  */
10972   if (!bfd_link_relocatable (flinfo->info)
10973       && ELF_ST_VISIBILITY (sym.st_other) != STV_DEFAULT
10974       && ELF_ST_BIND (sym.st_info) != STB_WEAK
10975       && h->root.type == bfd_link_hash_undefined
10976       && !h->def_regular)
10977     {
10978       const char *msg;
10979 
10980       if (ELF_ST_VISIBILITY (sym.st_other) == STV_PROTECTED)
10981           /* xgettext:c-format */
10982           msg = _("%pB: protected symbol `%s' isn't defined");
10983       else if (ELF_ST_VISIBILITY (sym.st_other) == STV_INTERNAL)
10984           /* xgettext:c-format */
10985           msg = _("%pB: internal symbol `%s' isn't defined");
10986       else
10987           /* xgettext:c-format */
10988           msg = _("%pB: hidden symbol `%s' isn't defined");
10989       _bfd_error_handler (msg, flinfo->output_bfd, h->root.root.string);
10990       bfd_set_error (bfd_error_bad_value);
10991       eoinfo->failed = true;
10992       return false;
10993     }
10994 
10995   /* If this symbol should be put in the .dynsym section, then put it
10996      there now.  We already know the symbol index.  We also fill in
10997      the entry in the .hash section.  */
10998   if (h->dynindx != -1
10999       && elf_hash_table (flinfo->info)->dynamic_sections_created
11000       && elf_hash_table (flinfo->info)->dynsym != NULL
11001       && !discarded_section (elf_hash_table (flinfo->info)->dynsym))
11002     {
11003       bfd_byte *esym;
11004 
11005       /* Since there is no version information in the dynamic string,
11006            if there is no version info in symbol version section, we will
11007            have a run-time problem if not linking executable, referenced
11008            by shared library, or not bound locally.  */
11009       if (h->verinfo.verdef == NULL
11010             && (!bfd_link_executable (flinfo->info)
11011                 || h->ref_dynamic
11012                 || !h->def_regular))
11013           {
11014             char *p = strrchr (h->root.root.string, ELF_VER_CHR);
11015 
11016             if (p && p [1] != '\0')
11017               {
11018                 _bfd_error_handler
11019                     /* xgettext:c-format */
11020                     (_("%pB: no symbol version section for versioned symbol `%s'"),
11021                      flinfo->output_bfd, h->root.root.string);
11022                 eoinfo->failed = true;
11023                 return false;
11024               }
11025           }
11026 
11027       sym.st_name = h->dynstr_index;
11028       esym = (elf_hash_table (flinfo->info)->dynsym->contents
11029                 + h->dynindx * bed->s->sizeof_sym);
11030       if (!check_dynsym (flinfo->output_bfd, &sym))
11031           {
11032             eoinfo->failed = true;
11033             return false;
11034           }
11035 
11036       /* Inform the linker of the addition of this symbol.  */
11037 
11038       if (flinfo->info->callbacks->ctf_new_dynsym)
11039           flinfo->info->callbacks->ctf_new_dynsym (h->dynindx, &sym);
11040 
11041       bed->s->swap_symbol_out (flinfo->output_bfd, &sym, esym, 0);
11042 
11043       if (flinfo->hash_sec != NULL)
11044           {
11045             size_t hash_entry_size;
11046             bfd_byte *bucketpos;
11047             bfd_vma chain;
11048             size_t bucketcount;
11049             size_t bucket;
11050 
11051             bucketcount = elf_hash_table (flinfo->info)->bucketcount;
11052             bucket = h->u.elf_hash_value % bucketcount;
11053 
11054             hash_entry_size
11055               = elf_section_data (flinfo->hash_sec)->this_hdr.sh_entsize;
11056             bucketpos = ((bfd_byte *) flinfo->hash_sec->contents
11057                            + (bucket + 2) * hash_entry_size);
11058             chain = bfd_get (8 * hash_entry_size, flinfo->output_bfd, bucketpos);
11059             bfd_put (8 * hash_entry_size, flinfo->output_bfd, h->dynindx,
11060                        bucketpos);
11061             bfd_put (8 * hash_entry_size, flinfo->output_bfd, chain,
11062                        ((bfd_byte *) flinfo->hash_sec->contents
11063                         + (bucketcount + 2 + h->dynindx) * hash_entry_size));
11064           }
11065 
11066       if (flinfo->symver_sec != NULL && flinfo->symver_sec->contents != NULL)
11067           {
11068             Elf_Internal_Versym iversym;
11069             Elf_External_Versym *eversym;
11070 
11071             if (!h->def_regular && !ELF_COMMON_DEF_P (h))
11072               {
11073                 if (h->verinfo.verdef == NULL
11074                       || (elf_dyn_lib_class (h->verinfo.verdef->vd_bfd)
11075                           & (DYN_AS_NEEDED | DYN_DT_NEEDED | DYN_NO_NEEDED)))
11076                     iversym.vs_vers = 1;
11077                 else
11078                     iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
11079               }
11080             else
11081               {
11082                 if (h->verinfo.vertree == NULL)
11083                     iversym.vs_vers = 1;
11084                 else
11085                     iversym.vs_vers = h->verinfo.vertree->vernum + 1;
11086                 if (flinfo->info->create_default_symver)
11087                     iversym.vs_vers++;
11088               }
11089 
11090             /* Turn on VERSYM_HIDDEN only if the hidden versioned symbol is
11091                defined locally.  */
11092             if (h->versioned == versioned_hidden && h->def_regular)
11093               iversym.vs_vers |= VERSYM_HIDDEN;
11094 
11095             eversym = (Elf_External_Versym *) flinfo->symver_sec->contents;
11096             eversym += h->dynindx;
11097             _bfd_elf_swap_versym_out (flinfo->output_bfd, &iversym, eversym);
11098           }
11099     }
11100 
11101   /* If the symbol is undefined, and we didn't output it to .dynsym,
11102      strip it from .symtab too.  Obviously we can't do this for
11103      relocatable output or when needed for --emit-relocs.  */
11104   else if (input_sec == bfd_und_section_ptr
11105              && h->indx != -2
11106              /* PR 22319 Do not strip global undefined symbols marked as being needed.  */
11107              && (h->mark != 1 || ELF_ST_BIND (sym.st_info) != STB_GLOBAL)
11108              && !bfd_link_relocatable (flinfo->info))
11109     return true;
11110 
11111   /* Also strip others that we couldn't earlier due to dynamic symbol
11112      processing.  */
11113   if (strip)
11114     return true;
11115   if ((input_sec->flags & SEC_EXCLUDE) != 0)
11116     return true;
11117 
11118   /* Output a FILE symbol so that following locals are not associated
11119      with the wrong input file.  We need one for forced local symbols
11120      if we've seen more than one FILE symbol or when we have exactly
11121      one FILE symbol but global symbols are present in a file other
11122      than the one with the FILE symbol.  We also need one if linker
11123      defined symbols are present.  In practice these conditions are
11124      always met, so just emit the FILE symbol unconditionally.  */
11125   if (eoinfo->localsyms
11126       && !eoinfo->file_sym_done
11127       && eoinfo->flinfo->filesym_count != 0)
11128     {
11129       Elf_Internal_Sym fsym;
11130 
11131       memset (&fsym, 0, sizeof (fsym));
11132       fsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
11133       fsym.st_shndx = SHN_ABS;
11134       if (!elf_link_output_symstrtab (eoinfo->flinfo, NULL, &fsym,
11135                                               bfd_und_section_ptr, NULL))
11136           return false;
11137 
11138       eoinfo->file_sym_done = true;
11139     }
11140 
11141   indx = bfd_get_symcount (flinfo->output_bfd);
11142   ret = elf_link_output_symstrtab (flinfo, h->root.root.string, &sym,
11143                                            input_sec, h);
11144   if (ret == 0)
11145     {
11146       eoinfo->failed = true;
11147       return false;
11148     }
11149   else if (ret == 1)
11150     h->indx = indx;
11151   else if (h->indx == -2)
11152     abort();
11153 
11154   return true;
11155 }
11156 
11157 /* Return TRUE if special handling is done for relocs in SEC against
11158    symbols defined in discarded sections.  */
11159 
11160 static bool
elf_section_ignore_discarded_relocs(asection * sec)11161 elf_section_ignore_discarded_relocs (asection *sec)
11162 {
11163   const struct elf_backend_data *bed;
11164 
11165   switch (sec->sec_info_type)
11166     {
11167     case SEC_INFO_TYPE_STABS:
11168     case SEC_INFO_TYPE_EH_FRAME:
11169     case SEC_INFO_TYPE_EH_FRAME_ENTRY:
11170     case SEC_INFO_TYPE_SFRAME:
11171       return true;
11172     default:
11173       break;
11174     }
11175 
11176   bed = get_elf_backend_data (sec->owner);
11177   if (bed->elf_backend_ignore_discarded_relocs != NULL
11178       && (*bed->elf_backend_ignore_discarded_relocs) (sec))
11179     return true;
11180 
11181   return false;
11182 }
11183 
11184 /* Return a mask saying how ld should treat relocations in SEC against
11185    symbols defined in discarded sections.  If this function returns
11186    COMPLAIN set, ld will issue a warning message.  If this function
11187    returns PRETEND set, and the discarded section was link-once and the
11188    same size as the kept link-once section, ld will pretend that the
11189    symbol was actually defined in the kept section.  Otherwise ld will
11190    zero the reloc (at least that is the intent, but some cooperation by
11191    the target dependent code is needed, particularly for REL targets).  */
11192 
11193 unsigned int
_bfd_elf_default_action_discarded(asection * sec)11194 _bfd_elf_default_action_discarded (asection *sec)
11195 {
11196   const struct elf_backend_data *bed;
11197   bed = get_elf_backend_data (sec->owner);
11198 
11199   if (sec->flags & SEC_DEBUGGING)
11200     return PRETEND;
11201 
11202   if (strcmp (".eh_frame", sec->name) == 0)
11203     return 0;
11204 
11205   if (bed->elf_backend_can_make_multiple_eh_frame
11206       && strncmp (sec->name, ".eh_frame.", 10) == 0)
11207     return 0;
11208 
11209   if (strcmp (".sframe", sec->name) == 0)
11210     return 0;
11211 
11212   if (strcmp (".gcc_except_table", sec->name) == 0)
11213     return 0;
11214 
11215   return COMPLAIN | PRETEND;
11216 }
11217 
11218 /* Find a match between a section and a member of a section group.  */
11219 
11220 static asection *
match_group_member(asection * sec,asection * group,struct bfd_link_info * info)11221 match_group_member (asection *sec, asection *group,
11222                         struct bfd_link_info *info)
11223 {
11224   asection *first = elf_next_in_group (group);
11225   asection *s = first;
11226 
11227   while (s != NULL)
11228     {
11229       if (bfd_elf_match_symbols_in_sections (s, sec, info))
11230           return s;
11231 
11232       s = elf_next_in_group (s);
11233       if (s == first)
11234           break;
11235     }
11236 
11237   return NULL;
11238 }
11239 
11240 /* Check if the kept section of a discarded section SEC can be used
11241    to replace it.  Return the replacement if it is OK.  Otherwise return
11242    NULL.  */
11243 
11244 asection *
_bfd_elf_check_kept_section(asection * sec,struct bfd_link_info * info)11245 _bfd_elf_check_kept_section (asection *sec, struct bfd_link_info *info)
11246 {
11247   asection *kept;
11248 
11249   kept = sec->kept_section;
11250   if (kept != NULL)
11251     {
11252       if ((kept->flags & SEC_GROUP) != 0)
11253           kept = match_group_member (sec, kept, info);
11254       if (kept != NULL)
11255           {
11256             if ((sec->rawsize != 0 ? sec->rawsize : sec->size)
11257                 != (kept->rawsize != 0 ? kept->rawsize : kept->size))
11258               kept = NULL;
11259             else
11260               {
11261                 /* Get the real kept section.  */
11262                 asection *next;
11263                 for (next = kept->kept_section;
11264                        next != NULL;
11265                        next = next->kept_section)
11266                     kept = next;
11267               }
11268           }
11269       sec->kept_section = kept;
11270     }
11271   return kept;
11272 }
11273 
11274 /* Link an input file into the linker output file.  This function
11275    handles all the sections and relocations of the input file at once.
11276    This is so that we only have to read the local symbols once, and
11277    don't have to keep them in memory.  */
11278 
11279 static bool
elf_link_input_bfd(struct elf_final_link_info * flinfo,bfd * input_bfd)11280 elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
11281 {
11282   int (*relocate_section)
11283     (bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
11284      Elf_Internal_Rela *, Elf_Internal_Sym *, asection **);
11285   bfd *output_bfd;
11286   Elf_Internal_Shdr *symtab_hdr;
11287   size_t locsymcount;
11288   size_t extsymoff;
11289   Elf_Internal_Sym *isymbuf;
11290   Elf_Internal_Sym *isym;
11291   Elf_Internal_Sym *isymend;
11292   long *pindex;
11293   asection **ppsection;
11294   asection *o;
11295   const struct elf_backend_data *bed;
11296   struct elf_link_hash_entry **sym_hashes;
11297   bfd_size_type address_size;
11298   bfd_vma r_type_mask;
11299   int r_sym_shift;
11300   bool have_file_sym = false;
11301 
11302   output_bfd = flinfo->output_bfd;
11303   bed = get_elf_backend_data (output_bfd);
11304   relocate_section = bed->elf_backend_relocate_section;
11305 
11306   /* If this is a dynamic object, we don't want to do anything here:
11307      we don't want the local symbols, and we don't want the section
11308      contents.  */
11309   if ((input_bfd->flags & DYNAMIC) != 0)
11310     return true;
11311 
11312   symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
11313   if (elf_bad_symtab (input_bfd))
11314     {
11315       locsymcount = symtab_hdr->sh_size / bed->s->sizeof_sym;
11316       extsymoff = 0;
11317     }
11318   else
11319     {
11320       locsymcount = symtab_hdr->sh_info;
11321       extsymoff = symtab_hdr->sh_info;
11322     }
11323 
11324   /* Enable GNU OSABI features in the output BFD that are used in the input
11325      BFD.  */
11326   if (bed->elf_osabi == ELFOSABI_NONE
11327       || bed->elf_osabi == ELFOSABI_GNU
11328       || bed->elf_osabi == ELFOSABI_FREEBSD)
11329     elf_tdata (output_bfd)->has_gnu_osabi
11330       |= (elf_tdata (input_bfd)->has_gnu_osabi
11331             & (bfd_link_relocatable (flinfo->info)
11332                ? -1 : ~elf_gnu_osabi_retain));
11333 
11334   /* Read the local symbols.  */
11335   isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
11336   if (isymbuf == NULL && locsymcount != 0)
11337     {
11338       isymbuf = bfd_elf_get_elf_syms (input_bfd, symtab_hdr, locsymcount, 0,
11339                                               flinfo->internal_syms,
11340                                               flinfo->external_syms,
11341                                               flinfo->locsym_shndx);
11342       if (isymbuf == NULL)
11343           return false;
11344     }
11345 
11346   /* Find local symbol sections and adjust values of symbols in
11347      SEC_MERGE sections.  Write out those local symbols we know are
11348      going into the output file.  */
11349   isymend = PTR_ADD (isymbuf, locsymcount);
11350   for (isym = isymbuf, pindex = flinfo->indices, ppsection = flinfo->sections;
11351        isym < isymend;
11352        isym++, pindex++, ppsection++)
11353     {
11354       asection *isec;
11355       const char *name;
11356       Elf_Internal_Sym osym;
11357       long indx;
11358       int ret;
11359 
11360       *pindex = -1;
11361 
11362       if (elf_bad_symtab (input_bfd))
11363           {
11364             if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
11365               {
11366                 *ppsection = NULL;
11367                 continue;
11368               }
11369           }
11370 
11371       if (isym->st_shndx == SHN_UNDEF)
11372           isec = bfd_und_section_ptr;
11373       else if (isym->st_shndx == SHN_ABS)
11374           isec = bfd_abs_section_ptr;
11375       else if (isym->st_shndx == SHN_COMMON)
11376           isec = bfd_com_section_ptr;
11377       else
11378           {
11379             isec = bfd_section_from_elf_index (input_bfd, isym->st_shndx);
11380             if (isec == NULL)
11381               {
11382                 /* Don't attempt to output symbols with st_shnx in the
11383                      reserved range other than SHN_ABS and SHN_COMMON.  */
11384                 isec = bfd_und_section_ptr;
11385               }
11386             else if (isec->sec_info_type == SEC_INFO_TYPE_MERGE
11387                        && ELF_ST_TYPE (isym->st_info) != STT_SECTION)
11388               isym->st_value =
11389                 _bfd_merged_section_offset (output_bfd, &isec,
11390                                                     elf_section_data (isec)->sec_info,
11391                                                     isym->st_value);
11392           }
11393 
11394       *ppsection = isec;
11395 
11396       /* Don't output the first, undefined, symbol.  In fact, don't
11397            output any undefined local symbol.  */
11398       if (isec == bfd_und_section_ptr)
11399           continue;
11400 
11401       if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
11402           {
11403             /* We never output section symbols.  Instead, we use the
11404                section symbol of the corresponding section in the output
11405                file.  */
11406             continue;
11407           }
11408 
11409       /* If we are stripping all symbols, we don't want to output this
11410            one.  */
11411       if (flinfo->info->strip == strip_all)
11412           continue;
11413 
11414       /* If we are discarding all local symbols, we don't want to
11415            output this one.  If we are generating a relocatable output
11416            file, then some of the local symbols may be required by
11417            relocs; we output them below as we discover that they are
11418            needed.  */
11419       if (flinfo->info->discard == discard_all)
11420           continue;
11421 
11422       /* If this symbol is defined in a section which we are
11423            discarding, we don't need to keep it.  */
11424       if (isym->st_shndx < SHN_LORESERVE
11425             && (isec->output_section == NULL
11426                 || bfd_section_removed_from_list (output_bfd,
11427                                                             isec->output_section)))
11428           continue;
11429 
11430       /* Get the name of the symbol.  */
11431       name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
11432                                                         isym->st_name);
11433       if (name == NULL)
11434           return false;
11435 
11436       /* See if we are discarding symbols with this name.  */
11437       if ((flinfo->info->strip == strip_some
11438              && (bfd_hash_lookup (flinfo->info->keep_hash, name, false, false)
11439                  == NULL))
11440             || (((flinfo->info->discard == discard_sec_merge
11441                     && (isec->flags & SEC_MERGE)
11442                     && !bfd_link_relocatable (flinfo->info))
11443                  || flinfo->info->discard == discard_l)
11444                 && bfd_is_local_label_name (input_bfd, name)))
11445           continue;
11446 
11447       if (ELF_ST_TYPE (isym->st_info) == STT_FILE)
11448           {
11449             if (input_bfd->lto_output)
11450               /* -flto puts a temp file name here.  This means builds
11451                  are not reproducible.  Discard the symbol.  */
11452               continue;
11453             have_file_sym = true;
11454             flinfo->filesym_count += 1;
11455           }
11456       if (!have_file_sym)
11457           {
11458             /* In the absence of debug info, bfd_find_nearest_line uses
11459                FILE symbols to determine the source file for local
11460                function symbols.  Provide a FILE symbol here if input
11461                files lack such, so that their symbols won't be
11462                associated with a previous input file.  It's not the
11463                source file, but the best we can do.  */
11464             const char *filename;
11465             have_file_sym = true;
11466             flinfo->filesym_count += 1;
11467             memset (&osym, 0, sizeof (osym));
11468             osym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
11469             osym.st_shndx = SHN_ABS;
11470             if (input_bfd->lto_output)
11471               filename = NULL;
11472             else
11473               filename = lbasename (bfd_get_filename (input_bfd));
11474             if (!elf_link_output_symstrtab (flinfo, filename, &osym,
11475                                                     bfd_abs_section_ptr, NULL))
11476               return false;
11477           }
11478 
11479       osym = *isym;
11480 
11481       /* Adjust the section index for the output file.  */
11482       osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
11483                                                                        isec->output_section);
11484       if (osym.st_shndx == SHN_BAD)
11485           return false;
11486 
11487       /* ELF symbols in relocatable files are section relative, but
11488            in executable files they are virtual addresses.  Note that
11489            this code assumes that all ELF sections have an associated
11490            BFD section with a reasonable value for output_offset; below
11491            we assume that they also have a reasonable value for
11492            output_section.  Any special sections must be set up to meet
11493            these requirements.  */
11494       osym.st_value += isec->output_offset;
11495       if (!bfd_link_relocatable (flinfo->info))
11496           {
11497             osym.st_value += isec->output_section->vma;
11498             if (ELF_ST_TYPE (osym.st_info) == STT_TLS)
11499               {
11500                 /* STT_TLS symbols are relative to PT_TLS segment base.  */
11501                 if (elf_hash_table (flinfo->info)->tls_sec != NULL)
11502                     osym.st_value -= elf_hash_table (flinfo->info)->tls_sec->vma;
11503                 else
11504                     osym.st_info = ELF_ST_INFO (ELF_ST_BIND (osym.st_info),
11505                                                       STT_NOTYPE);
11506               }
11507           }
11508 
11509       indx = bfd_get_symcount (output_bfd);
11510       ret = elf_link_output_symstrtab (flinfo, name, &osym, isec, NULL);
11511       if (ret == 0)
11512           return false;
11513       else if (ret == 1)
11514           *pindex = indx;
11515     }
11516 
11517   if (bed->s->arch_size == 32)
11518     {
11519       r_type_mask = 0xff;
11520       r_sym_shift = 8;
11521       address_size = 4;
11522     }
11523   else
11524     {
11525       r_type_mask = 0xffffffff;
11526       r_sym_shift = 32;
11527       address_size = 8;
11528     }
11529 
11530   /* Relocate the contents of each section.  */
11531   sym_hashes = elf_sym_hashes (input_bfd);
11532   for (o = input_bfd->sections; o != NULL; o = o->next)
11533     {
11534       bfd_byte *contents;
11535 
11536       if (! o->linker_mark)
11537           {
11538             /* This section was omitted from the link.  */
11539             continue;
11540           }
11541 
11542       if (!flinfo->info->resolve_section_groups
11543             && (o->flags & (SEC_LINKER_CREATED | SEC_GROUP)) == SEC_GROUP)
11544           {
11545             /* Deal with the group signature symbol.  */
11546             struct bfd_elf_section_data *sec_data = elf_section_data (o);
11547             unsigned long symndx = sec_data->this_hdr.sh_info;
11548             asection *osec = o->output_section;
11549 
11550             BFD_ASSERT (bfd_link_relocatable (flinfo->info));
11551             if (symndx >= locsymcount
11552                 || (elf_bad_symtab (input_bfd)
11553                       && flinfo->sections[symndx] == NULL))
11554               {
11555                 struct elf_link_hash_entry *h = sym_hashes[symndx - extsymoff];
11556                 while (h->root.type == bfd_link_hash_indirect
11557                          || h->root.type == bfd_link_hash_warning)
11558                     h = (struct elf_link_hash_entry *) h->root.u.i.link;
11559                 /* Arrange for symbol to be output.  */
11560                 h->indx = -2;
11561                 elf_section_data (osec)->this_hdr.sh_info = -2;
11562               }
11563             else if (ELF_ST_TYPE (isymbuf[symndx].st_info) == STT_SECTION)
11564               {
11565                 /* We'll use the output section target_index.  */
11566                 asection *sec = flinfo->sections[symndx]->output_section;
11567                 elf_section_data (osec)->this_hdr.sh_info = sec->target_index;
11568               }
11569             else
11570               {
11571                 if (flinfo->indices[symndx] == -1)
11572                     {
11573                       /* Otherwise output the local symbol now.  */
11574                       Elf_Internal_Sym sym = isymbuf[symndx];
11575                       asection *sec = flinfo->sections[symndx]->output_section;
11576                       const char *name;
11577                       long indx;
11578                       int ret;
11579 
11580                       name = bfd_elf_string_from_elf_section (input_bfd,
11581                                                                         symtab_hdr->sh_link,
11582                                                                         sym.st_name);
11583                       if (name == NULL)
11584                         return false;
11585 
11586                       sym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
11587                                                                                     sec);
11588                       if (sym.st_shndx == SHN_BAD)
11589                         return false;
11590 
11591                       sym.st_value += o->output_offset;
11592 
11593                       indx = bfd_get_symcount (output_bfd);
11594                       ret = elf_link_output_symstrtab (flinfo, name, &sym, o,
11595                                                                NULL);
11596                       if (ret == 0)
11597                         return false;
11598                       else if (ret == 1)
11599                         flinfo->indices[symndx] = indx;
11600                       else
11601                         abort ();
11602                     }
11603                 elf_section_data (osec)->this_hdr.sh_info
11604                     = flinfo->indices[symndx];
11605               }
11606           }
11607 
11608       if ((o->flags & SEC_HAS_CONTENTS) == 0
11609             || (o->size == 0 && (o->flags & SEC_RELOC) == 0))
11610           continue;
11611 
11612       if ((o->flags & SEC_LINKER_CREATED) != 0)
11613           {
11614             /* Section was created by _bfd_elf_link_create_dynamic_sections
11615                or somesuch.  */
11616             continue;
11617           }
11618 
11619       /* Get the contents of the section.  They have been cached by a
11620            relaxation routine.  Note that o is a section in an input
11621            file, so the contents field will not have been set by any of
11622            the routines which work on output files.  */
11623       if (elf_section_data (o)->this_hdr.contents != NULL)
11624           {
11625             contents = elf_section_data (o)->this_hdr.contents;
11626             if (bed->caches_rawsize
11627                 && o->rawsize != 0
11628                 && o->rawsize < o->size)
11629               {
11630                 memcpy (flinfo->contents, contents, o->rawsize);
11631                 contents = flinfo->contents;
11632               }
11633           }
11634       else if (!(o->flags & SEC_RELOC)
11635                  && !bed->elf_backend_write_section
11636                  && o->sec_info_type == SEC_INFO_TYPE_MERGE)
11637           /* A MERGE section that has no relocations doesn't need the
11638              contents anymore, they have been recorded earlier.  Except
11639              if the backend has special provisions for writing sections.  */
11640           contents = NULL;
11641       else
11642           {
11643             contents = flinfo->contents;
11644             if (! _bfd_elf_link_mmap_section_contents (input_bfd, o,
11645                                                                  &contents))
11646               return false;
11647           }
11648 
11649       if ((o->flags & SEC_RELOC) != 0)
11650           {
11651             Elf_Internal_Rela *internal_relocs;
11652             Elf_Internal_Rela *rel, *relend;
11653             int action_discarded;
11654             int ret;
11655 
11656             /* Get the swapped relocs.  */
11657             internal_relocs
11658               = _bfd_elf_link_info_read_relocs (input_bfd, flinfo->info, o,
11659                                                         flinfo->external_relocs,
11660                                                         flinfo->internal_relocs,
11661                                                         false);
11662             if (internal_relocs == NULL
11663                 && o->reloc_count > 0)
11664               return false;
11665 
11666             action_discarded = -1;
11667             if (!elf_section_ignore_discarded_relocs (o))
11668               action_discarded = (*bed->action_discarded) (o);
11669 
11670             /* Run through the relocs evaluating complex reloc symbols and
11671                looking for relocs against symbols from discarded sections
11672                or section symbols from removed link-once sections.
11673                Complain about relocs against discarded sections.  Zero
11674                relocs against removed link-once sections.  */
11675 
11676             rel = internal_relocs;
11677             relend = rel + o->reloc_count;
11678             for ( ; rel < relend; rel++)
11679               {
11680                 unsigned long r_symndx = rel->r_info >> r_sym_shift;
11681                 unsigned int s_type;
11682                 asection **ps, *sec;
11683                 struct elf_link_hash_entry *h = NULL;
11684                 const char *sym_name;
11685 
11686                 if (r_symndx == STN_UNDEF)
11687                     continue;
11688 
11689                 if (r_symndx >= locsymcount
11690                       || (elf_bad_symtab (input_bfd)
11691                           && flinfo->sections[r_symndx] == NULL))
11692                     {
11693                       h = sym_hashes[r_symndx - extsymoff];
11694 
11695                       /* Badly formatted input files can contain relocs that
11696                          reference non-existant symbols.  Check here so that
11697                          we do not seg fault.  */
11698                       if (h == NULL)
11699                         {
11700                           _bfd_error_handler
11701                               /* xgettext:c-format */
11702                               (_("error: %pB contains a reloc (%#" PRIx64 ") for section %pA "
11703                                  "that references a non-existent global symbol"),
11704                                input_bfd, (uint64_t) rel->r_info, o);
11705                           bfd_set_error (bfd_error_bad_value);
11706                           return false;
11707                         }
11708 
11709                       while (h->root.type == bfd_link_hash_indirect
11710                                || h->root.type == bfd_link_hash_warning)
11711                         h = (struct elf_link_hash_entry *) h->root.u.i.link;
11712 
11713                       s_type = h->type;
11714 
11715                       /* If a plugin symbol is referenced from a non-IR file,
11716                          mark the symbol as undefined.  Note that the
11717                          linker may attach linker created dynamic sections
11718                          to the plugin bfd.  Symbols defined in linker
11719                          created sections are not plugin symbols.  */
11720                       if ((h->root.non_ir_ref_regular
11721                            || h->root.non_ir_ref_dynamic)
11722                           && (h->root.type == bfd_link_hash_defined
11723                                 || h->root.type == bfd_link_hash_defweak)
11724                           && (h->root.u.def.section->flags
11725                                 & SEC_LINKER_CREATED) == 0
11726                           && h->root.u.def.section->owner != NULL
11727                           && (h->root.u.def.section->owner->flags
11728                                 & BFD_PLUGIN) != 0)
11729                         {
11730                           h->root.type = bfd_link_hash_undefined;
11731                           h->root.u.undef.abfd = h->root.u.def.section->owner;
11732                         }
11733 
11734                       ps = NULL;
11735                       if (h->root.type == bfd_link_hash_defined
11736                           || h->root.type == bfd_link_hash_defweak)
11737                         ps = &h->root.u.def.section;
11738 
11739                       sym_name = h->root.root.string;
11740                     }
11741                 else
11742                     {
11743                       Elf_Internal_Sym *sym = isymbuf + r_symndx;
11744 
11745                       s_type = ELF_ST_TYPE (sym->st_info);
11746                       ps = &flinfo->sections[r_symndx];
11747                       sym_name = bfd_elf_sym_name (input_bfd, symtab_hdr,
11748                                                          sym, *ps);
11749                     }
11750 
11751                 if ((s_type == STT_RELC || s_type == STT_SRELC)
11752                       && !bfd_link_relocatable (flinfo->info))
11753                     {
11754                       bfd_vma val;
11755                       bfd_vma dot = (rel->r_offset
11756                                          + o->output_offset + o->output_section->vma);
11757 #ifdef DEBUG
11758                       printf ("Encountered a complex symbol!");
11759                       printf (" (input_bfd %s, section %s, reloc %ld\n",
11760                                 bfd_get_filename (input_bfd), o->name,
11761                                 (long) (rel - internal_relocs));
11762                       printf (" symbol: idx  %8.8lx, name %s\n",
11763                                 r_symndx, sym_name);
11764                       printf (" reloc : info %8.8lx, addr %8.8lx\n",
11765                                 (unsigned long) rel->r_info,
11766                                 (unsigned long) rel->r_offset);
11767 #endif
11768                       if (!eval_symbol (&val, &sym_name, input_bfd, flinfo, dot,
11769                                             isymbuf, locsymcount, s_type == STT_SRELC))
11770                         return false;
11771 
11772                       /* Symbol evaluated OK.  Update to absolute value.  */
11773                       set_symbol_value (input_bfd, isymbuf, locsymcount,
11774                                             r_symndx, val);
11775                       continue;
11776                     }
11777 
11778                 if (action_discarded != -1 && ps != NULL)
11779                     {
11780                       /* Complain if the definition comes from a
11781                          discarded section.  */
11782                       if ((sec = *ps) != NULL && discarded_section (sec))
11783                         {
11784                           BFD_ASSERT (r_symndx != STN_UNDEF);
11785                           if (action_discarded & COMPLAIN)
11786                               (*flinfo->info->callbacks->einfo)
11787                                 /* xgettext:c-format */
11788                                 (_("%X`%s' referenced in section `%pA' of %pB: "
11789                                    "defined in discarded section `%pA' of %pB\n"),
11790                                  sym_name, o, input_bfd, sec, sec->owner);
11791 
11792                           /* Try to do the best we can to support buggy old
11793                                versions of gcc.  Pretend that the symbol is
11794                                really defined in the kept linkonce section.
11795                                FIXME: This is quite broken.  Modifying the
11796                                symbol here means we will be changing all later
11797                                uses of the symbol, not just in this section.  */
11798                           if (action_discarded & PRETEND)
11799                               {
11800                                 asection *kept;
11801 
11802                                 kept = _bfd_elf_check_kept_section (sec,
11803                                                                             flinfo->info);
11804                                 if (kept != NULL)
11805                                   {
11806                                     *ps = kept;
11807                                     continue;
11808                                   }
11809                               }
11810                         }
11811                     }
11812               }
11813 
11814             /* Relocate the section by invoking a back end routine.
11815 
11816                The back end routine is responsible for adjusting the
11817                section contents as necessary, and (if using Rela relocs
11818                and generating a relocatable output file) adjusting the
11819                reloc addend as necessary.
11820 
11821                The back end routine does not have to worry about setting
11822                the reloc address or the reloc symbol index.
11823 
11824                The back end routine is given a pointer to the swapped in
11825                internal symbols, and can access the hash table entries
11826                for the external symbols via elf_sym_hashes (input_bfd).
11827 
11828                When generating relocatable output, the back end routine
11829                must handle STB_LOCAL/STT_SECTION symbols specially.  The
11830                output symbol is going to be a section symbol
11831                corresponding to the output section, which will require
11832                the addend to be adjusted.  */
11833 
11834             ret = (*relocate_section) (output_bfd, flinfo->info,
11835                                              input_bfd, o, contents,
11836                                              internal_relocs,
11837                                              isymbuf,
11838                                              flinfo->sections);
11839             if (!ret)
11840               return false;
11841 
11842             if (ret == 2
11843                 || bfd_link_relocatable (flinfo->info)
11844                 || flinfo->info->emitrelocations)
11845               {
11846                 Elf_Internal_Rela *irela;
11847                 Elf_Internal_Rela *irelaend, *irelamid;
11848                 bfd_vma last_offset;
11849                 struct elf_link_hash_entry **rel_hash;
11850                 struct elf_link_hash_entry **rel_hash_list, **rela_hash_list;
11851                 Elf_Internal_Shdr *input_rel_hdr, *input_rela_hdr;
11852                 unsigned int next_erel;
11853                 bool rela_normal;
11854                 struct bfd_elf_section_data *esdi, *esdo;
11855 
11856                 esdi = elf_section_data (o);
11857                 esdo = elf_section_data (o->output_section);
11858                 rela_normal = false;
11859 
11860                 /* Adjust the reloc addresses and symbol indices.  */
11861 
11862                 irela = internal_relocs;
11863                 irelaend = irela + o->reloc_count;
11864                 rel_hash = PTR_ADD (esdo->rel.hashes, esdo->rel.count);
11865                 /* We start processing the REL relocs, if any.  When we reach
11866                      IRELAMID in the loop, we switch to the RELA relocs.  */
11867                 irelamid = irela;
11868                 if (esdi->rel.hdr != NULL)
11869                     irelamid += (NUM_SHDR_ENTRIES (esdi->rel.hdr)
11870                                    * bed->s->int_rels_per_ext_rel);
11871                 rel_hash_list = rel_hash;
11872                 rela_hash_list = NULL;
11873                 last_offset = o->output_offset;
11874                 if (!bfd_link_relocatable (flinfo->info))
11875                     last_offset += o->output_section->vma;
11876                 for (next_erel = 0; irela < irelaend; irela++, next_erel++)
11877                     {
11878                       unsigned long r_symndx;
11879                       asection *sec;
11880                       Elf_Internal_Sym sym;
11881 
11882                       if (next_erel == bed->s->int_rels_per_ext_rel)
11883                         {
11884                           rel_hash++;
11885                           next_erel = 0;
11886                         }
11887 
11888                       if (irela == irelamid)
11889                         {
11890                           rel_hash = PTR_ADD (esdo->rela.hashes, esdo->rela.count);
11891                           rela_hash_list = rel_hash;
11892                           if (bed->is_rela_normal != NULL)
11893                               rela_normal = bed->is_rela_normal (irela);
11894                           else
11895                               rela_normal = bed->rela_normal;
11896                         }
11897 
11898                       irela->r_offset = _bfd_elf_section_offset (output_bfd,
11899                                                                            flinfo->info, o,
11900                                                                            irela->r_offset);
11901                       if (irela->r_offset >= (bfd_vma) -2)
11902                         {
11903                           /* This is a reloc for a deleted entry or somesuch.
11904                                Turn it into an R_*_NONE reloc, at the same
11905                                offset as the last reloc.  elf_eh_frame.c and
11906                                bfd_elf_discard_info rely on reloc offsets
11907                                being ordered.  */
11908                           irela->r_offset = last_offset;
11909                           irela->r_info = 0;
11910                           irela->r_addend = 0;
11911                           continue;
11912                         }
11913 
11914                       irela->r_offset += o->output_offset;
11915 
11916                       /* Relocs in an executable have to be virtual addresses.  */
11917                       if (!bfd_link_relocatable (flinfo->info))
11918                         irela->r_offset += o->output_section->vma;
11919 
11920                       last_offset = irela->r_offset;
11921 
11922                       r_symndx = irela->r_info >> r_sym_shift;
11923                       if (r_symndx == STN_UNDEF)
11924                         continue;
11925 
11926                       if (r_symndx >= locsymcount
11927                           || (elf_bad_symtab (input_bfd)
11928                                 && flinfo->sections[r_symndx] == NULL))
11929                         {
11930                           struct elf_link_hash_entry *rh;
11931                           unsigned long indx;
11932 
11933                           /* This is a reloc against a global symbol.  We
11934                                have not yet output all the local symbols, so
11935                                we do not know the symbol index of any global
11936                                symbol.  We set the rel_hash entry for this
11937                                reloc to point to the global hash table entry
11938                                for this symbol.  The symbol index is then
11939                                set at the end of bfd_elf_final_link.  */
11940                           indx = r_symndx - extsymoff;
11941                           rh = elf_sym_hashes (input_bfd)[indx];
11942                           while (rh->root.type == bfd_link_hash_indirect
11943                                    || rh->root.type == bfd_link_hash_warning)
11944                               rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
11945 
11946                           /* Setting the index to -2 tells
11947                                elf_link_output_extsym that this symbol is
11948                                used by a reloc.  */
11949                           BFD_ASSERT (rh->indx < 0);
11950                           rh->indx = -2;
11951                           *rel_hash = rh;
11952 
11953                           continue;
11954                         }
11955 
11956                       /* This is a reloc against a local symbol.  */
11957 
11958                       *rel_hash = NULL;
11959                       sym = isymbuf[r_symndx];
11960                       sec = flinfo->sections[r_symndx];
11961                       if (ELF_ST_TYPE (sym.st_info) == STT_SECTION)
11962                         {
11963                           /* I suppose the backend ought to fill in the
11964                                section of any STT_SECTION symbol against a
11965                                processor specific section.  */
11966                           r_symndx = STN_UNDEF;
11967                           if (bfd_is_abs_section (sec))
11968                               ;
11969                           else if (sec == NULL || sec->owner == NULL)
11970                               {
11971                                 bfd_set_error (bfd_error_bad_value);
11972                                 return false;
11973                               }
11974                           else
11975                               {
11976                                 asection *osec = sec->output_section;
11977 
11978                                 /* If we have discarded a section, the output
11979                                    section will be the absolute section.  In
11980                                    case of discarded SEC_MERGE sections, use
11981                                    the kept section.  relocate_section should
11982                                    have already handled discarded linkonce
11983                                    sections.  */
11984                                 if (bfd_is_abs_section (osec)
11985                                     && sec->kept_section != NULL
11986                                     && sec->kept_section->output_section != NULL)
11987                                   {
11988                                     osec = sec->kept_section->output_section;
11989                                     irela->r_addend -= osec->vma;
11990                                   }
11991 
11992                                 if (!bfd_is_abs_section (osec))
11993                                   {
11994                                     r_symndx = osec->target_index;
11995                                     if (r_symndx == STN_UNDEF)
11996                                         {
11997                                           irela->r_addend += osec->vma;
11998                                           osec = _bfd_nearby_section (output_bfd, osec,
11999                                                                             osec->vma);
12000                                           irela->r_addend -= osec->vma;
12001                                           r_symndx = osec->target_index;
12002                                         }
12003                                   }
12004                               }
12005 
12006                           /* Adjust the addend according to where the
12007                                section winds up in the output section.  */
12008                           if (rela_normal)
12009                               irela->r_addend += sec->output_offset;
12010                         }
12011                       else
12012                         {
12013                           if (flinfo->indices[r_symndx] == -1)
12014                               {
12015                                 unsigned long shlink;
12016                                 const char *name;
12017                                 asection *osec;
12018                                 long indx;
12019 
12020                                 if (flinfo->info->strip == strip_all)
12021                                   {
12022                                     /* You can't do ld -r -s.  */
12023                                     bfd_set_error (bfd_error_invalid_operation);
12024                                     return false;
12025                                   }
12026 
12027                                 /* This symbol was skipped earlier, but
12028                                    since it is needed by a reloc, we
12029                                    must output it now.  */
12030                                 shlink = symtab_hdr->sh_link;
12031                                 name = (bfd_elf_string_from_elf_section
12032                                           (input_bfd, shlink, sym.st_name));
12033                                 if (name == NULL)
12034                                   return false;
12035 
12036                                 osec = sec->output_section;
12037                                 sym.st_shndx =
12038                                   _bfd_elf_section_from_bfd_section (output_bfd,
12039                                                                              osec);
12040                                 if (sym.st_shndx == SHN_BAD)
12041                                   return false;
12042 
12043                                 sym.st_value += sec->output_offset;
12044                                 if (!bfd_link_relocatable (flinfo->info))
12045                                   {
12046                                     sym.st_value += osec->vma;
12047                                     if (ELF_ST_TYPE (sym.st_info) == STT_TLS)
12048                                         {
12049                                           struct elf_link_hash_table *htab
12050                                             = elf_hash_table (flinfo->info);
12051 
12052                                           /* STT_TLS symbols are relative to PT_TLS
12053                                              segment base.  */
12054                                           if (htab->tls_sec != NULL)
12055                                             sym.st_value -= htab->tls_sec->vma;
12056                                           else
12057                                             sym.st_info
12058                                               = ELF_ST_INFO (ELF_ST_BIND (sym.st_info),
12059                                                                  STT_NOTYPE);
12060                                         }
12061                                   }
12062 
12063                                 indx = bfd_get_symcount (output_bfd);
12064                                 ret = elf_link_output_symstrtab (flinfo, name,
12065                                                                          &sym, sec,
12066                                                                          NULL);
12067                                 if (ret == 0)
12068                                   return false;
12069                                 else if (ret == 1)
12070                                   flinfo->indices[r_symndx] = indx;
12071                                 else
12072                                   abort ();
12073                               }
12074 
12075                           r_symndx = flinfo->indices[r_symndx];
12076                         }
12077 
12078                       irela->r_info = ((bfd_vma) r_symndx << r_sym_shift
12079                                            | (irela->r_info & r_type_mask));
12080                     }
12081 
12082                 /* Swap out the relocs.  */
12083                 input_rel_hdr = esdi->rel.hdr;
12084                 if (input_rel_hdr && input_rel_hdr->sh_size != 0)
12085                     {
12086                       if (!bed->elf_backend_emit_relocs (output_bfd, o,
12087                                                                  input_rel_hdr,
12088                                                                  internal_relocs,
12089                                                                  rel_hash_list))
12090                         return false;
12091                       internal_relocs += (NUM_SHDR_ENTRIES (input_rel_hdr)
12092                                               * bed->s->int_rels_per_ext_rel);
12093                       rel_hash_list += NUM_SHDR_ENTRIES (input_rel_hdr);
12094                     }
12095 
12096                 input_rela_hdr = esdi->rela.hdr;
12097                 if (input_rela_hdr && input_rela_hdr->sh_size != 0)
12098                     {
12099                       if (!bed->elf_backend_emit_relocs (output_bfd, o,
12100                                                                  input_rela_hdr,
12101                                                                  internal_relocs,
12102                                                                  rela_hash_list))
12103                         return false;
12104                     }
12105               }
12106           }
12107 
12108       /* Write out the modified section contents.  */
12109       if (bed->elf_backend_write_section
12110             && (*bed->elf_backend_write_section) (output_bfd, flinfo->info, o,
12111                                                             contents))
12112           {
12113             /* Section written out.  */
12114           }
12115       else switch (o->sec_info_type)
12116           {
12117           case SEC_INFO_TYPE_STABS:
12118             if (! (_bfd_write_section_stabs
12119                      (output_bfd,
12120                       &elf_hash_table (flinfo->info)->stab_info,
12121                       o, &elf_section_data (o)->sec_info, contents)))
12122               return false;
12123             break;
12124           case SEC_INFO_TYPE_MERGE:
12125             if (! _bfd_write_merged_section (output_bfd, o,
12126                                                      elf_section_data (o)->sec_info))
12127               return false;
12128             break;
12129           case SEC_INFO_TYPE_EH_FRAME:
12130             {
12131               if (! _bfd_elf_write_section_eh_frame (output_bfd, flinfo->info,
12132                                                                o, contents))
12133                 return false;
12134             }
12135             break;
12136           case SEC_INFO_TYPE_EH_FRAME_ENTRY:
12137             {
12138               if (! _bfd_elf_write_section_eh_frame_entry (output_bfd,
12139                                                                        flinfo->info,
12140                                                                        o, contents))
12141                 return false;
12142             }
12143             break;
12144           case SEC_INFO_TYPE_SFRAME:
12145               {
12146                 /* Merge .sframe sections into the ctf frame encoder
12147                      context of the output_bfd's section.  The final .sframe
12148                      output section will be written out later.  */
12149                 if (!_bfd_elf_merge_section_sframe (output_bfd, flinfo->info,
12150                                                               o, contents))
12151                     return false;
12152               }
12153               break;
12154           default:
12155             {
12156               if (! (o->flags & SEC_EXCLUDE))
12157                 {
12158                     file_ptr offset = (file_ptr) o->output_offset;
12159                     bfd_size_type todo = o->size;
12160 
12161                     offset *= bfd_octets_per_byte (output_bfd, o);
12162 
12163                     if ((o->flags & SEC_ELF_REVERSE_COPY)
12164                         && o->size > address_size)
12165                       {
12166                         /* Reverse-copy input section to output.  */
12167 
12168                         if ((o->size & (address_size - 1)) != 0
12169                               || (o->reloc_count != 0
12170                                   && (o->size * bed->s->int_rels_per_ext_rel
12171                                         != o->reloc_count * address_size)))
12172                           {
12173                               _bfd_error_handler
12174                                 /* xgettext:c-format */
12175                                 (_("error: %pB: size of section %pA is not "
12176                                    "multiple of address size"),
12177                                  input_bfd, o);
12178                               bfd_set_error (bfd_error_bad_value);
12179                               return false;
12180                           }
12181 
12182                         do
12183                           {
12184                               todo -= address_size;
12185                               if (! bfd_set_section_contents (output_bfd,
12186                                                                       o->output_section,
12187                                                                       contents + todo,
12188                                                                       offset,
12189                                                                       address_size))
12190                                 return false;
12191                               if (todo == 0)
12192                                 break;
12193                               offset += address_size;
12194                           }
12195                         while (1);
12196                       }
12197                     else if (! bfd_set_section_contents (output_bfd,
12198                                                                  o->output_section,
12199                                                                  contents,
12200                                                                  offset, todo))
12201                       return false;
12202                 }
12203             }
12204             break;
12205           }
12206 
12207       /* Munmap the section contents for each input section.  */
12208       _bfd_elf_link_munmap_section_contents (o);
12209     }
12210 
12211   return true;
12212 }
12213 
12214 /* Generate a reloc when linking an ELF file.  This is a reloc
12215    requested by the linker, and does not come from any input file.  This
12216    is used to build constructor and destructor tables when linking
12217    with -Ur.  */
12218 
12219 static bool
elf_reloc_link_order(bfd * output_bfd,struct bfd_link_info * info,asection * output_section,struct bfd_link_order * link_order)12220 elf_reloc_link_order (bfd *output_bfd,
12221                           struct bfd_link_info *info,
12222                           asection *output_section,
12223                           struct bfd_link_order *link_order)
12224 {
12225   reloc_howto_type *howto;
12226   long indx;
12227   bfd_vma offset;
12228   bfd_vma addend;
12229   struct bfd_elf_section_reloc_data *reldata;
12230   struct elf_link_hash_entry **rel_hash_ptr;
12231   Elf_Internal_Shdr *rel_hdr;
12232   const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
12233   Elf_Internal_Rela irel[MAX_INT_RELS_PER_EXT_REL];
12234   bfd_byte *erel;
12235   unsigned int i;
12236   struct bfd_elf_section_data *esdo = elf_section_data (output_section);
12237 
12238   howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
12239   if (howto == NULL)
12240     {
12241       bfd_set_error (bfd_error_bad_value);
12242       return false;
12243     }
12244 
12245   addend = link_order->u.reloc.p->addend;
12246 
12247   if (esdo->rel.hdr)
12248     reldata = &esdo->rel;
12249   else if (esdo->rela.hdr)
12250     reldata = &esdo->rela;
12251   else
12252     {
12253       reldata = NULL;
12254       BFD_ASSERT (0);
12255     }
12256 
12257   /* Figure out the symbol index.  */
12258   rel_hash_ptr = reldata->hashes + reldata->count;
12259   if (link_order->type == bfd_section_reloc_link_order)
12260     {
12261       indx = link_order->u.reloc.p->u.section->target_index;
12262       BFD_ASSERT (indx != 0);
12263       *rel_hash_ptr = NULL;
12264     }
12265   else
12266     {
12267       struct elf_link_hash_entry *h;
12268 
12269       /* Treat a reloc against a defined symbol as though it were
12270            actually against the section.  */
12271       h = ((struct elf_link_hash_entry *)
12272              bfd_wrapped_link_hash_lookup (output_bfd, info,
12273                                                    link_order->u.reloc.p->u.name,
12274                                                    false, false, true));
12275       if (h != NULL
12276             && (h->root.type == bfd_link_hash_defined
12277                 || h->root.type == bfd_link_hash_defweak))
12278           {
12279             asection *section;
12280 
12281             section = h->root.u.def.section;
12282             indx = section->output_section->target_index;
12283             *rel_hash_ptr = NULL;
12284             /* It seems that we ought to add the symbol value to the
12285                addend here, but in practice it has already been added
12286                because it was passed to constructor_callback.  */
12287             addend += section->output_section->vma + section->output_offset;
12288           }
12289       else if (h != NULL)
12290           {
12291             /* Setting the index to -2 tells elf_link_output_extsym that
12292                this symbol is used by a reloc.  */
12293             h->indx = -2;
12294             *rel_hash_ptr = h;
12295             indx = 0;
12296           }
12297       else
12298           {
12299             (*info->callbacks->unattached_reloc)
12300               (info, link_order->u.reloc.p->u.name, NULL, NULL, 0);
12301             indx = 0;
12302           }
12303     }
12304 
12305   /* If this is an inplace reloc, we must write the addend into the
12306      object file.  */
12307   if (howto->partial_inplace && addend != 0)
12308     {
12309       bfd_size_type size;
12310       bfd_reloc_status_type rstat;
12311       bfd_byte *buf;
12312       bool ok;
12313       const char *sym_name;
12314       bfd_size_type octets;
12315 
12316       size = (bfd_size_type) bfd_get_reloc_size (howto);
12317       buf = (bfd_byte *) bfd_zmalloc (size);
12318       if (buf == NULL && size != 0)
12319           return false;
12320       rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
12321       switch (rstat)
12322           {
12323           case bfd_reloc_ok:
12324             break;
12325 
12326           default:
12327           case bfd_reloc_outofrange:
12328             abort ();
12329 
12330           case bfd_reloc_overflow:
12331             if (link_order->type == bfd_section_reloc_link_order)
12332               sym_name = bfd_section_name (link_order->u.reloc.p->u.section);
12333             else
12334               sym_name = link_order->u.reloc.p->u.name;
12335             (*info->callbacks->reloc_overflow) (info, NULL, sym_name,
12336                                                         howto->name, addend, NULL, NULL,
12337                                                         (bfd_vma) 0);
12338             break;
12339           }
12340 
12341       octets = link_order->offset * bfd_octets_per_byte (output_bfd,
12342                                                                        output_section);
12343       ok = bfd_set_section_contents (output_bfd, output_section, buf,
12344                                              octets, size);
12345       free (buf);
12346       if (! ok)
12347           return false;
12348     }
12349 
12350   /* The address of a reloc is relative to the section in a
12351      relocatable file, and is a virtual address in an executable
12352      file.  */
12353   offset = link_order->offset;
12354   if (! bfd_link_relocatable (info))
12355     offset += output_section->vma;
12356 
12357   for (i = 0; i < bed->s->int_rels_per_ext_rel; i++)
12358     {
12359       irel[i].r_offset = offset;
12360       irel[i].r_info = 0;
12361       irel[i].r_addend = 0;
12362     }
12363   if (bed->s->arch_size == 32)
12364     irel[0].r_info = ELF32_R_INFO (indx, howto->type);
12365   else
12366     irel[0].r_info = ELF64_R_INFO (indx, howto->type);
12367 
12368   rel_hdr = reldata->hdr;
12369   erel = rel_hdr->contents;
12370   if (rel_hdr->sh_type == SHT_REL)
12371     {
12372       erel += reldata->count * bed->s->sizeof_rel;
12373       (*bed->s->swap_reloc_out) (output_bfd, irel, erel);
12374     }
12375   else
12376     {
12377       irel[0].r_addend = addend;
12378       erel += reldata->count * bed->s->sizeof_rela;
12379       (*bed->s->swap_reloca_out) (output_bfd, irel, erel);
12380     }
12381 
12382   ++reldata->count;
12383 
12384   return true;
12385 }
12386 
12387 /* Generate an import library in INFO->implib_bfd from symbols in ABFD.
12388    Returns TRUE upon success, FALSE otherwise.  */
12389 
12390 static bool
elf_output_implib(bfd * abfd,struct bfd_link_info * info)12391 elf_output_implib (bfd *abfd, struct bfd_link_info *info)
12392 {
12393   bool ret = false;
12394   bfd *implib_bfd;
12395   const struct elf_backend_data *bed;
12396   flagword flags;
12397   enum bfd_architecture arch;
12398   unsigned int mach;
12399   asymbol **sympp = NULL;
12400   long symsize;
12401   long symcount;
12402   long src_count;
12403   elf_symbol_type *osymbuf;
12404   size_t amt;
12405 
12406   implib_bfd = info->out_implib_bfd;
12407   bed = get_elf_backend_data (abfd);
12408 
12409   if (!bfd_set_format (implib_bfd, bfd_object))
12410     return false;
12411 
12412   /* Use flag from executable but make it a relocatable object.  */
12413   flags = bfd_get_file_flags (abfd);
12414   flags &= ~HAS_RELOC;
12415   if (!bfd_set_start_address (implib_bfd, 0)
12416       || !bfd_set_file_flags (implib_bfd, flags & ~EXEC_P))
12417     return false;
12418 
12419   /* Copy architecture of output file to import library file.  */
12420   arch = bfd_get_arch (abfd);
12421   mach = bfd_get_mach (abfd);
12422   if (!bfd_set_arch_mach (implib_bfd, arch, mach)
12423       && (abfd->target_defaulted
12424             || bfd_get_arch (abfd) != bfd_get_arch (implib_bfd)))
12425     return false;
12426 
12427   /* Get symbol table size.  */
12428   symsize = bfd_get_symtab_upper_bound (abfd);
12429   if (symsize < 0)
12430     return false;
12431 
12432   /* Read in the symbol table.  */
12433   sympp = (asymbol **) bfd_malloc (symsize);
12434   if (sympp == NULL)
12435     return false;
12436 
12437   symcount = bfd_canonicalize_symtab (abfd, sympp);
12438   if (symcount < 0)
12439     goto free_sym_buf;
12440 
12441   /* Allow the BFD backend to copy any private header data it
12442      understands from the output BFD to the import library BFD.  */
12443   if (! bfd_copy_private_header_data (abfd, implib_bfd))
12444     goto free_sym_buf;
12445 
12446   /* Filter symbols to appear in the import library.  */
12447   if (bed->elf_backend_filter_implib_symbols)
12448     symcount = bed->elf_backend_filter_implib_symbols (abfd, info, sympp,
12449                                                                    symcount);
12450   else
12451     symcount = _bfd_elf_filter_global_symbols (abfd, info, sympp, symcount);
12452   if (symcount == 0)
12453     {
12454       bfd_set_error (bfd_error_no_symbols);
12455       _bfd_error_handler (_("%pB: no symbol found for import library"),
12456                                 implib_bfd);
12457       goto free_sym_buf;
12458     }
12459 
12460 
12461   /* Make symbols absolute.  */
12462   amt = symcount * sizeof (*osymbuf);
12463   osymbuf = (elf_symbol_type *) bfd_alloc (implib_bfd, amt);
12464   if (osymbuf == NULL)
12465     goto free_sym_buf;
12466 
12467   for (src_count = 0; src_count < symcount; src_count++)
12468     {
12469       memcpy (&osymbuf[src_count], (elf_symbol_type *) sympp[src_count],
12470                 sizeof (*osymbuf));
12471       osymbuf[src_count].symbol.section = bfd_abs_section_ptr;
12472       osymbuf[src_count].internal_elf_sym.st_shndx = SHN_ABS;
12473       osymbuf[src_count].symbol.value += sympp[src_count]->section->vma;
12474       osymbuf[src_count].internal_elf_sym.st_value =
12475           osymbuf[src_count].symbol.value;
12476       sympp[src_count] = &osymbuf[src_count].symbol;
12477     }
12478 
12479   bfd_set_symtab (implib_bfd, sympp, symcount);
12480 
12481   /* Allow the BFD backend to copy any private data it understands
12482      from the output BFD to the import library BFD.  This is done last
12483      to permit the routine to look at the filtered symbol table.  */
12484   if (! bfd_copy_private_bfd_data (abfd, implib_bfd))
12485     goto free_sym_buf;
12486 
12487   if (!bfd_close (implib_bfd))
12488     goto free_sym_buf;
12489 
12490   ret = true;
12491 
12492  free_sym_buf:
12493   free (sympp);
12494   return ret;
12495 }
12496 
12497 static void
elf_final_link_free(bfd * obfd,struct elf_final_link_info * flinfo)12498 elf_final_link_free (bfd *obfd, struct elf_final_link_info *flinfo)
12499 {
12500   asection *o;
12501 
12502   if (flinfo->symstrtab != NULL)
12503     _bfd_elf_strtab_free (flinfo->symstrtab);
12504   free (flinfo->contents);
12505   free (flinfo->external_relocs);
12506   free (flinfo->internal_relocs);
12507   free (flinfo->external_syms);
12508   free (flinfo->locsym_shndx);
12509   free (flinfo->internal_syms);
12510   free (flinfo->indices);
12511   free (flinfo->sections);
12512   if (flinfo->symshndxbuf != (Elf_External_Sym_Shndx *) -1)
12513     free (flinfo->symshndxbuf);
12514   for (o = obfd->sections; o != NULL; o = o->next)
12515     {
12516       struct bfd_elf_section_data *esdo = elf_section_data (o);
12517       free (esdo->rel.hashes);
12518       free (esdo->rela.hashes);
12519     }
12520 }
12521 
12522 /* Do the final step of an ELF link.  */
12523 
12524 bool
bfd_elf_final_link(bfd * abfd,struct bfd_link_info * info)12525 bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
12526 {
12527   bool dynamic;
12528   bool emit_relocs;
12529   bfd *dynobj;
12530   struct elf_final_link_info flinfo;
12531   asection *o;
12532   struct bfd_link_order *p;
12533   bfd *sub;
12534   bfd_size_type max_contents_size;
12535   bfd_size_type max_external_reloc_size;
12536   bfd_size_type max_internal_reloc_count;
12537   bfd_size_type max_sym_count;
12538   bfd_size_type max_sym_shndx_count;
12539   Elf_Internal_Sym elfsym;
12540   unsigned int i;
12541   Elf_Internal_Shdr *symtab_hdr;
12542   Elf_Internal_Shdr *symtab_shndx_hdr;
12543   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
12544   struct elf_outext_info eoinfo;
12545   bool merged;
12546   size_t relativecount;
12547   size_t relr_entsize;
12548   asection *reldyn = 0;
12549   bfd_size_type amt;
12550   asection *attr_section = NULL;
12551   bfd_vma attr_size = 0;
12552   const char *std_attrs_section;
12553   struct elf_link_hash_table *htab = elf_hash_table (info);
12554   bool sections_removed;
12555   bool ret;
12556 
12557   if (!is_elf_hash_table (&htab->root))
12558     return false;
12559 
12560   if (bfd_link_pic (info))
12561     abfd->flags |= DYNAMIC;
12562 
12563   dynamic = htab->dynamic_sections_created;
12564   dynobj = htab->dynobj;
12565 
12566   emit_relocs = (bfd_link_relocatable (info)
12567                      || info->emitrelocations);
12568 
12569   memset (&flinfo, 0, sizeof (flinfo));
12570   flinfo.info = info;
12571   flinfo.output_bfd = abfd;
12572   flinfo.symstrtab = _bfd_elf_strtab_init ();
12573   if (flinfo.symstrtab == NULL)
12574     return false;
12575 
12576   if (! dynamic)
12577     {
12578       flinfo.hash_sec = NULL;
12579       flinfo.symver_sec = NULL;
12580     }
12581   else
12582     {
12583       flinfo.hash_sec = bfd_get_linker_section (dynobj, ".hash");
12584       /* Note that dynsym_sec can be NULL (on VMS).  */
12585       flinfo.symver_sec = bfd_get_linker_section (dynobj, ".gnu.version");
12586       /* Note that it is OK if symver_sec is NULL.  */
12587     }
12588 
12589   if (info->unique_symbol
12590       && !bfd_hash_table_init (&flinfo.local_hash_table,
12591                                      local_hash_newfunc,
12592                                      sizeof (struct local_hash_entry)))
12593     return false;
12594 
12595   /* The object attributes have been merged.  Remove the input
12596      sections from the link, and set the contents of the output
12597      section.  */
12598   sections_removed = false;
12599   std_attrs_section = get_elf_backend_data (abfd)->obj_attrs_section;
12600   for (o = abfd->sections; o != NULL; o = o->next)
12601     {
12602       bool remove_section = false;
12603 
12604       if ((std_attrs_section && strcmp (o->name, std_attrs_section) == 0)
12605             || strcmp (o->name, ".gnu.attributes") == 0)
12606           {
12607             for (p = o->map_head.link_order; p != NULL; p = p->next)
12608               {
12609                 asection *input_section;
12610 
12611                 if (p->type != bfd_indirect_link_order)
12612                     continue;
12613                 input_section = p->u.indirect.section;
12614                 /* Hack: reset the SEC_HAS_CONTENTS flag so that
12615                      elf_link_input_bfd ignores this section.  */
12616                 input_section->flags &= ~SEC_HAS_CONTENTS;
12617               }
12618 
12619             attr_size = bfd_elf_obj_attr_size (abfd);
12620             bfd_set_section_size (o, attr_size);
12621             /* Skip this section later on.  */
12622             o->map_head.link_order = NULL;
12623             if (attr_size)
12624               attr_section = o;
12625             else
12626               remove_section = true;
12627           }
12628       else if ((o->flags & SEC_GROUP) != 0 && o->size == 0)
12629           {
12630             /* Remove empty group section from linker output.  */
12631             remove_section = true;
12632           }
12633       if (remove_section)
12634           {
12635             o->flags |= SEC_EXCLUDE;
12636             bfd_section_list_remove (abfd, o);
12637             abfd->section_count--;
12638             sections_removed = true;
12639           }
12640     }
12641   if (sections_removed)
12642     _bfd_fix_excluded_sec_syms (abfd, info);
12643 
12644   /* Count up the number of relocations we will output for each output
12645      section, so that we know the sizes of the reloc sections.  We
12646      also figure out some maximum sizes.  */
12647 #ifdef USE_MMAP
12648   if (bed->use_mmap)
12649     {
12650       /* Mmap is used only if section size >= the minimum mmap section
12651            size.  The initial max_contents_size value covers all sections
12652            smaller than the minimum mmap section size.  It may be increased
12653            for compressed or linker created sections or sections whose
12654            rawsize != size.  max_external_reloc_size covers all relocation
12655            sections smaller than the minimum mmap section size.  */
12656       max_contents_size = _bfd_minimum_mmap_size;
12657       max_external_reloc_size = _bfd_minimum_mmap_size;
12658     }
12659   else
12660 #endif
12661     {
12662       max_contents_size = 0;
12663       max_external_reloc_size = 0;
12664     }
12665   max_internal_reloc_count = 0;
12666   max_sym_count = 0;
12667   max_sym_shndx_count = 0;
12668   merged = false;
12669   for (o = abfd->sections; o != NULL; o = o->next)
12670     {
12671       struct bfd_elf_section_data *esdo = elf_section_data (o);
12672       o->reloc_count = 0;
12673 
12674       for (p = o->map_head.link_order; p != NULL; p = p->next)
12675           {
12676             unsigned int reloc_count = 0;
12677             unsigned int additional_reloc_count = 0;
12678             struct bfd_elf_section_data *esdi = NULL;
12679 
12680             if (p->type == bfd_section_reloc_link_order
12681                 || p->type == bfd_symbol_reloc_link_order)
12682               reloc_count = 1;
12683             else if (p->type == bfd_indirect_link_order)
12684               {
12685                 asection *sec;
12686 
12687                 sec = p->u.indirect.section;
12688 
12689                 /* Mark all sections which are to be included in the
12690                      link.  This will normally be every section.  We need
12691                      to do this so that we can identify any sections which
12692                      the linker has decided to not include.  */
12693                 sec->linker_mark = true;
12694 
12695                 if (sec->flags & SEC_MERGE)
12696                     merged = true;
12697 
12698 #ifdef USE_MMAP
12699                 /* Mmap is used only on non-compressed, non-linker created
12700                      sections whose rawsize == size.  */
12701                 if (!bed->use_mmap
12702                       || sec->compress_status != COMPRESS_SECTION_NONE
12703                       || (sec->flags & SEC_LINKER_CREATED) != 0
12704                       || sec->rawsize != sec->size)
12705 #endif
12706                     {
12707                       if (sec->rawsize > max_contents_size)
12708                         max_contents_size = sec->rawsize;
12709                       if (sec->size > max_contents_size)
12710                         max_contents_size = sec->size;
12711                     }
12712 
12713                 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
12714                       && (sec->owner->flags & DYNAMIC) == 0)
12715                     {
12716                       size_t sym_count;
12717 
12718                       /* We are interested in just local symbols, not all
12719                          symbols.  */
12720                       if (elf_bad_symtab (sec->owner))
12721                         sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
12722                                          / bed->s->sizeof_sym);
12723                       else
12724                         sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
12725 
12726                       if (sym_count > max_sym_count)
12727                         max_sym_count = sym_count;
12728 
12729                       if (sym_count > max_sym_shndx_count
12730                           && elf_symtab_shndx_list (sec->owner) != NULL)
12731                         max_sym_shndx_count = sym_count;
12732 
12733                       esdi = elf_section_data (sec);
12734 
12735                       if (esdi->this_hdr.sh_type == SHT_REL
12736                           || esdi->this_hdr.sh_type == SHT_RELA)
12737                         /* Some backends use reloc_count in relocation sections
12738                            to count particular types of relocs.  Of course,
12739                            reloc sections themselves can't have relocations.  */
12740                         ;
12741                       else if (emit_relocs)
12742                         {
12743                           reloc_count = sec->reloc_count;
12744                           if (bed->elf_backend_count_additional_relocs)
12745                               {
12746                                 int c;
12747                                 c = (*bed->elf_backend_count_additional_relocs) (sec);
12748                                 additional_reloc_count += c;
12749                               }
12750                         }
12751                       else if (bed->elf_backend_count_relocs)
12752                         reloc_count = (*bed->elf_backend_count_relocs) (info, sec);
12753 
12754                       if ((sec->flags & SEC_RELOC) != 0)
12755                         {
12756 #ifdef USE_MMAP
12757                           if (!bed->use_mmap)
12758 #endif
12759                               {
12760                                 size_t ext_size = 0;
12761 
12762                                 if (esdi->rel.hdr != NULL)
12763                                   ext_size = esdi->rel.hdr->sh_size;
12764                                 if (esdi->rela.hdr != NULL)
12765                                   ext_size += esdi->rela.hdr->sh_size;
12766 
12767                                 if (ext_size > max_external_reloc_size)
12768                                   max_external_reloc_size = ext_size;
12769                               }
12770                           if (sec->reloc_count > max_internal_reloc_count)
12771                               max_internal_reloc_count = sec->reloc_count;
12772                         }
12773                     }
12774               }
12775 
12776             if (reloc_count == 0)
12777               continue;
12778 
12779             reloc_count += additional_reloc_count;
12780             o->reloc_count += reloc_count;
12781 
12782             if (p->type == bfd_indirect_link_order && emit_relocs)
12783               {
12784                 if (esdi->rel.hdr)
12785                     {
12786                       esdo->rel.count += NUM_SHDR_ENTRIES (esdi->rel.hdr);
12787                       esdo->rel.count += additional_reloc_count;
12788                     }
12789                 if (esdi->rela.hdr)
12790                     {
12791                       esdo->rela.count += NUM_SHDR_ENTRIES (esdi->rela.hdr);
12792                       esdo->rela.count += additional_reloc_count;
12793                     }
12794               }
12795             else
12796               {
12797                 if (o->use_rela_p)
12798                     esdo->rela.count += reloc_count;
12799                 else
12800                     esdo->rel.count += reloc_count;
12801               }
12802           }
12803 
12804       if (o->reloc_count > 0)
12805           o->flags |= SEC_RELOC;
12806       else
12807           {
12808             /* Explicitly clear the SEC_RELOC flag.  The linker tends to
12809                set it (this is probably a bug) and if it is set
12810                assign_section_numbers will create a reloc section.  */
12811             o->flags &=~ SEC_RELOC;
12812           }
12813 
12814       /* If the SEC_ALLOC flag is not set, force the section VMA to
12815            zero.  This is done in elf_fake_sections as well, but forcing
12816            the VMA to 0 here will ensure that relocs against these
12817            sections are handled correctly.  */
12818       if ((o->flags & SEC_ALLOC) == 0
12819             && ! o->user_set_vma)
12820           o->vma = 0;
12821     }
12822 
12823   if (! bfd_link_relocatable (info) && merged)
12824     elf_link_hash_traverse (htab, _bfd_elf_link_sec_merge_syms, abfd);
12825 
12826   /* Figure out the file positions for everything but the symbol table
12827      and the relocs.  We set symcount to force assign_section_numbers
12828      to create a symbol table.  */
12829   abfd->symcount = info->strip != strip_all || emit_relocs;
12830   BFD_ASSERT (! abfd->output_has_begun);
12831   if (! _bfd_elf_compute_section_file_positions (abfd, info))
12832     goto error_return;
12833 
12834   /* Set sizes, and assign file positions for reloc sections.  */
12835   for (o = abfd->sections; o != NULL; o = o->next)
12836     {
12837       struct bfd_elf_section_data *esdo = elf_section_data (o);
12838       if ((o->flags & SEC_RELOC) != 0)
12839           {
12840             if (esdo->rel.hdr
12841                 && !(_bfd_elf_link_size_reloc_section (abfd, &esdo->rel)))
12842               goto error_return;
12843 
12844             if (esdo->rela.hdr
12845                 && !(_bfd_elf_link_size_reloc_section (abfd, &esdo->rela)))
12846               goto error_return;
12847           }
12848 
12849       /* _bfd_elf_compute_section_file_positions makes temporary use
12850            of target_index.  Reset it.  */
12851       o->target_index = 0;
12852 
12853       /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
12854            to count upwards while actually outputting the relocations.  */
12855       esdo->rel.count = 0;
12856       esdo->rela.count = 0;
12857 
12858       if ((esdo->this_hdr.sh_offset == (file_ptr) -1)
12859             && !bfd_section_is_ctf (o))
12860           {
12861             /* Cache the section contents so that they can be compressed
12862                later.  Use bfd_malloc since it will be freed by
12863                bfd_compress_section_contents.  */
12864             unsigned char *contents = esdo->this_hdr.contents;
12865             if (contents != NULL)
12866               abort ();
12867             contents
12868               = (unsigned char *) bfd_malloc (esdo->this_hdr.sh_size);
12869             if (contents == NULL)
12870               goto error_return;
12871             esdo->this_hdr.contents = contents;
12872           }
12873     }
12874 
12875   /* We have now assigned file positions for all the sections except .symtab,
12876      .strtab, and non-loaded reloc and compressed debugging sections.  We start
12877      the .symtab section at the current file position, and write directly to it.
12878      We build the .strtab section in memory.  */
12879   abfd->symcount = 0;
12880   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
12881   /* sh_name is set in prep_headers.  */
12882   symtab_hdr->sh_type = SHT_SYMTAB;
12883   /* sh_flags, sh_addr and sh_size all start off zero.  */
12884   symtab_hdr->sh_entsize = bed->s->sizeof_sym;
12885   /* sh_link is set in assign_section_numbers.  */
12886   /* sh_info is set below.  */
12887   /* sh_offset is set just below.  */
12888   symtab_hdr->sh_addralign = (bfd_vma) 1 << bed->s->log_file_align;
12889 
12890   if (max_sym_count < 20)
12891     max_sym_count = 20;
12892   htab->strtabsize = max_sym_count;
12893   amt = max_sym_count * sizeof (struct elf_sym_strtab);
12894   htab->strtab = (struct elf_sym_strtab *) bfd_malloc (amt);
12895   if (htab->strtab == NULL)
12896     goto error_return;
12897   /* The real buffer will be allocated in elf_link_swap_symbols_out.  */
12898   flinfo.symshndxbuf
12899     = (elf_numsections (abfd) > (SHN_LORESERVE & 0xFFFF)
12900        ? (Elf_External_Sym_Shndx *) -1 : NULL);
12901 
12902   if (info->strip != strip_all || emit_relocs)
12903     {
12904       file_ptr off = elf_next_file_pos (abfd);
12905 
12906       _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
12907 
12908       /* Note that at this point elf_next_file_pos (abfd) is
12909            incorrect.  We do not yet know the size of the .symtab section.
12910            We correct next_file_pos below, after we do know the size.  */
12911 
12912       /* Start writing out the symbol table.  The first symbol is always a
12913            dummy symbol.  */
12914       elfsym.st_value = 0;
12915       elfsym.st_size = 0;
12916       elfsym.st_info = 0;
12917       elfsym.st_other = 0;
12918       elfsym.st_shndx = SHN_UNDEF;
12919       elfsym.st_target_internal = 0;
12920       if (elf_link_output_symstrtab (&flinfo, NULL, &elfsym,
12921                                              bfd_und_section_ptr, NULL) != 1)
12922           goto error_return;
12923 
12924       /* Output a symbol for each section if asked or they are used for
12925            relocs.  These symbols usually have no names.  We store the
12926            index of each one in the index field of the section, so that
12927            we can find it again when outputting relocs.  */
12928 
12929       if (bfd_keep_unused_section_symbols (abfd) || emit_relocs)
12930           {
12931             bool name_local_sections
12932               = (bed->elf_backend_name_local_section_symbols
12933                  && bed->elf_backend_name_local_section_symbols (abfd));
12934             const char *name = NULL;
12935 
12936             elfsym.st_size = 0;
12937             elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
12938             elfsym.st_other = 0;
12939             elfsym.st_value = 0;
12940             elfsym.st_target_internal = 0;
12941             for (i = 1; i < elf_numsections (abfd); i++)
12942               {
12943                 o = bfd_section_from_elf_index (abfd, i);
12944                 if (o != NULL)
12945                     {
12946                       o->target_index = bfd_get_symcount (abfd);
12947                       elfsym.st_shndx = i;
12948                       if (!bfd_link_relocatable (info))
12949                         elfsym.st_value = o->vma;
12950                       if (name_local_sections)
12951                         name = o->name;
12952                       if (elf_link_output_symstrtab (&flinfo, name, &elfsym, o,
12953                                                              NULL) != 1)
12954                         goto error_return;
12955                     }
12956               }
12957           }
12958     }
12959 
12960   /* On some targets like Irix 5 the symbol split between local and global
12961      ones recorded in the sh_info field needs to be done between section
12962      and all other symbols.  */
12963   if (bed->elf_backend_elfsym_local_is_section
12964       && bed->elf_backend_elfsym_local_is_section (abfd))
12965     symtab_hdr->sh_info = bfd_get_symcount (abfd);
12966 
12967   /* Allocate some memory to hold information read in from the input
12968      files.  */
12969   if (max_contents_size != 0)
12970     {
12971       flinfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
12972       if (flinfo.contents == NULL)
12973           goto error_return;
12974     }
12975 
12976   if (max_external_reloc_size != 0)
12977     {
12978       flinfo.external_relocs = bfd_malloc (max_external_reloc_size);
12979       if (flinfo.external_relocs == NULL)
12980           goto error_return;
12981     }
12982 
12983   if (max_internal_reloc_count != 0)
12984     {
12985       amt = max_internal_reloc_count * sizeof (Elf_Internal_Rela);
12986       flinfo.internal_relocs = (Elf_Internal_Rela *) bfd_malloc (amt);
12987       if (flinfo.internal_relocs == NULL)
12988           goto error_return;
12989     }
12990 
12991   if (max_sym_count != 0)
12992     {
12993       amt = max_sym_count * bed->s->sizeof_sym;
12994       flinfo.external_syms = (bfd_byte *) bfd_malloc (amt);
12995       if (flinfo.external_syms == NULL)
12996           goto error_return;
12997 
12998       amt = max_sym_count * sizeof (Elf_Internal_Sym);
12999       flinfo.internal_syms = (Elf_Internal_Sym *) bfd_malloc (amt);
13000       if (flinfo.internal_syms == NULL)
13001           goto error_return;
13002 
13003       amt = max_sym_count * sizeof (long);
13004       flinfo.indices = (long int *) bfd_malloc (amt);
13005       if (flinfo.indices == NULL)
13006           goto error_return;
13007 
13008       amt = max_sym_count * sizeof (asection *);
13009       flinfo.sections = (asection **) bfd_malloc (amt);
13010       if (flinfo.sections == NULL)
13011           goto error_return;
13012     }
13013 
13014   if (max_sym_shndx_count != 0)
13015     {
13016       amt = max_sym_shndx_count * sizeof (Elf_External_Sym_Shndx);
13017       flinfo.locsym_shndx = (Elf_External_Sym_Shndx *) bfd_malloc (amt);
13018       if (flinfo.locsym_shndx == NULL)
13019           goto error_return;
13020     }
13021 
13022   if (htab->tls_sec)
13023     {
13024       bfd_vma base, end = 0;  /* Both bytes.  */
13025       asection *sec;
13026 
13027       for (sec = htab->tls_sec;
13028              sec && (sec->flags & SEC_THREAD_LOCAL);
13029              sec = sec->next)
13030           {
13031             bfd_size_type size = sec->size;
13032             unsigned int opb = bfd_octets_per_byte (abfd, sec);
13033 
13034             if (size == 0
13035                 && (sec->flags & SEC_HAS_CONTENTS) == 0)
13036               {
13037                 struct bfd_link_order *ord = sec->map_tail.link_order;
13038 
13039                 if (ord != NULL)
13040                     size = ord->offset * opb + ord->size;
13041               }
13042             end = sec->vma + size / opb;
13043           }
13044       base = htab->tls_sec->vma;
13045       /* Only align end of TLS section if static TLS doesn't have special
13046            alignment requirements.  */
13047       if (bed->static_tls_alignment == 1)
13048           end = align_power (end, htab->tls_sec->alignment_power);
13049       htab->tls_size = end - base;
13050     }
13051 
13052   if (!_bfd_elf_fixup_eh_frame_hdr (info))
13053     return false;
13054 
13055   /* Finish relative relocations here after regular symbol processing
13056      is finished if DT_RELR is enabled.  */
13057   if (info->enable_dt_relr
13058       && bed->finish_relative_relocs
13059       && !bed->finish_relative_relocs (info))
13060     info->callbacks->einfo
13061       (_("%F%P: %pB: failed to finish relative relocations\n"), abfd);
13062 
13063   /* Since ELF permits relocations to be against local symbols, we
13064      must have the local symbols available when we do the relocations.
13065      Since we would rather only read the local symbols once, and we
13066      would rather not keep them in memory, we handle all the
13067      relocations for a single input file at the same time.
13068 
13069      Unfortunately, there is no way to know the total number of local
13070      symbols until we have seen all of them, and the local symbol
13071      indices precede the global symbol indices.  This means that when
13072      we are generating relocatable output, and we see a reloc against
13073      a global symbol, we can not know the symbol index until we have
13074      finished examining all the local symbols to see which ones we are
13075      going to output.  To deal with this, we keep the relocations in
13076      memory, and don't output them until the end of the link.  This is
13077      an unfortunate waste of memory, but I don't see a good way around
13078      it.  Fortunately, it only happens when performing a relocatable
13079      link, which is not the common case.  FIXME: If keep_memory is set
13080      we could write the relocs out and then read them again; I don't
13081      know how bad the memory loss will be.  */
13082 
13083   for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
13084     sub->output_has_begun = false;
13085   for (o = abfd->sections; o != NULL; o = o->next)
13086     {
13087       for (p = o->map_head.link_order; p != NULL; p = p->next)
13088           {
13089             if (p->type == bfd_indirect_link_order
13090                 && (bfd_get_flavour ((sub = p->u.indirect.section->owner))
13091                       == bfd_target_elf_flavour)
13092                 && elf_elfheader (sub)->e_ident[EI_CLASS] == bed->s->elfclass)
13093               {
13094                 if (! sub->output_has_begun)
13095                     {
13096                       if (! elf_link_input_bfd (&flinfo, sub))
13097                         goto error_return;
13098                       sub->output_has_begun = true;
13099                     }
13100               }
13101             else if (p->type == bfd_section_reloc_link_order
13102                        || p->type == bfd_symbol_reloc_link_order)
13103               {
13104                 if (! elf_reloc_link_order (abfd, info, o, p))
13105                     goto error_return;
13106               }
13107             else
13108               {
13109                 if (! _bfd_default_link_order (abfd, info, o, p))
13110                     {
13111                       if (p->type == bfd_indirect_link_order
13112                           && (bfd_get_flavour (sub)
13113                                 == bfd_target_elf_flavour)
13114                           && (elf_elfheader (sub)->e_ident[EI_CLASS]
13115                                 != bed->s->elfclass))
13116                         {
13117                           const char *iclass, *oclass;
13118 
13119                           switch (bed->s->elfclass)
13120                               {
13121                               case ELFCLASS64: oclass = "ELFCLASS64"; break;
13122                               case ELFCLASS32: oclass = "ELFCLASS32"; break;
13123                               case ELFCLASSNONE: oclass = "ELFCLASSNONE"; break;
13124                               default: abort ();
13125                               }
13126 
13127                           switch (elf_elfheader (sub)->e_ident[EI_CLASS])
13128                               {
13129                               case ELFCLASS64: iclass = "ELFCLASS64"; break;
13130                               case ELFCLASS32: iclass = "ELFCLASS32"; break;
13131                               case ELFCLASSNONE: iclass = "ELFCLASSNONE"; break;
13132                               default: abort ();
13133                               }
13134 
13135                           bfd_set_error (bfd_error_wrong_format);
13136                           _bfd_error_handler
13137                               /* xgettext:c-format */
13138                               (_("%pB: file class %s incompatible with %s"),
13139                                sub, iclass, oclass);
13140                         }
13141 
13142                       goto error_return;
13143                     }
13144               }
13145           }
13146     }
13147 
13148   /* Free symbol buffer if needed.  */
13149   if (!info->reduce_memory_overheads)
13150     {
13151       for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
13152           if (bfd_get_flavour (sub) == bfd_target_elf_flavour)
13153             {
13154               free (elf_tdata (sub)->symbuf);
13155               elf_tdata (sub)->symbuf = NULL;
13156             }
13157     }
13158 
13159   ret = true;
13160 
13161   /* Output any global symbols that got converted to local in a
13162      version script or due to symbol visibility.  We do this in a
13163      separate step since ELF requires all local symbols to appear
13164      prior to any global symbols.  FIXME: We should only do this if
13165      some global symbols were, in fact, converted to become local.
13166      FIXME: Will this work correctly with the Irix 5 linker?  */
13167   eoinfo.failed = false;
13168   eoinfo.flinfo = &flinfo;
13169   eoinfo.localsyms = true;
13170   eoinfo.file_sym_done = false;
13171   bfd_hash_traverse (&info->hash->table, elf_link_output_extsym, &eoinfo);
13172   if (eoinfo.failed)
13173     {
13174       ret = false;
13175       goto return_local_hash_table;
13176     }
13177 
13178   /* If backend needs to output some local symbols not present in the hash
13179      table, do it now.  */
13180   if (bed->elf_backend_output_arch_local_syms)
13181     {
13182       if (! ((*bed->elf_backend_output_arch_local_syms)
13183                (abfd, info, &flinfo, elf_link_output_symstrtab)))
13184           {
13185             ret = false;
13186             goto return_local_hash_table;
13187           }
13188     }
13189 
13190   /* That wrote out all the local symbols.  Finish up the symbol table
13191      with the global symbols. Even if we want to strip everything we
13192      can, we still need to deal with those global symbols that got
13193      converted to local in a version script.  */
13194 
13195   /* The sh_info field records the index of the first non local symbol.  */
13196   if (!symtab_hdr->sh_info)
13197     symtab_hdr->sh_info = bfd_get_symcount (abfd);
13198 
13199   if (dynamic
13200       && htab->dynsym != NULL
13201       && htab->dynsym->output_section != bfd_abs_section_ptr)
13202     {
13203       Elf_Internal_Sym sym;
13204       bfd_byte *dynsym = htab->dynsym->contents;
13205 
13206       o = htab->dynsym->output_section;
13207       elf_section_data (o)->this_hdr.sh_info = htab->local_dynsymcount + 1;
13208 
13209       /* Write out the section symbols for the output sections.  */
13210       if (bfd_link_pic (info)
13211             || htab->is_relocatable_executable)
13212           {
13213             asection *s;
13214 
13215             sym.st_size = 0;
13216             sym.st_name = 0;
13217             sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
13218             sym.st_other = 0;
13219             sym.st_target_internal = 0;
13220 
13221             for (s = abfd->sections; s != NULL; s = s->next)
13222               {
13223                 int indx;
13224                 bfd_byte *dest;
13225                 long dynindx;
13226 
13227                 dynindx = elf_section_data (s)->dynindx;
13228                 if (dynindx <= 0)
13229                     continue;
13230                 indx = elf_section_data (s)->this_idx;
13231                 BFD_ASSERT (indx > 0);
13232                 sym.st_shndx = indx;
13233                 if (! check_dynsym (abfd, &sym))
13234                     {
13235                       ret = false;
13236                       goto return_local_hash_table;
13237                     }
13238                 sym.st_value = s->vma;
13239                 dest = dynsym + dynindx * bed->s->sizeof_sym;
13240 
13241                 /* Inform the linker of the addition of this symbol.  */
13242 
13243                 if (info->callbacks->ctf_new_dynsym)
13244                     info->callbacks->ctf_new_dynsym (dynindx, &sym);
13245 
13246                 bed->s->swap_symbol_out (abfd, &sym, dest, 0);
13247               }
13248           }
13249 
13250       /* Write out the local dynsyms.  */
13251       if (htab->dynlocal)
13252           {
13253             struct elf_link_local_dynamic_entry *e;
13254             for (e = htab->dynlocal; e ; e = e->next)
13255               {
13256                 asection *s;
13257                 bfd_byte *dest;
13258 
13259                 /* Copy the internal symbol and turn off visibility.
13260                      Note that we saved a word of storage and overwrote
13261                      the original st_name with the dynstr_index.  */
13262                 sym = e->isym;
13263                 sym.st_other &= ~ELF_ST_VISIBILITY (-1);
13264                 sym.st_shndx = SHN_UNDEF;
13265 
13266                 s = bfd_section_from_elf_index (e->input_bfd,
13267                                                         e->isym.st_shndx);
13268                 if (s != NULL
13269                       && s->output_section != NULL
13270                       && elf_section_data (s->output_section) != NULL)
13271                     {
13272                       sym.st_shndx =
13273                         elf_section_data (s->output_section)->this_idx;
13274                       if (! check_dynsym (abfd, &sym))
13275                         {
13276                           ret = false;
13277                           goto return_local_hash_table;
13278                         }
13279                       sym.st_value = (s->output_section->vma
13280                                           + s->output_offset
13281                                           + e->isym.st_value);
13282                     }
13283 
13284                 /* Inform the linker of the addition of this symbol.  */
13285 
13286                 if (info->callbacks->ctf_new_dynsym)
13287                     info->callbacks->ctf_new_dynsym (e->dynindx, &sym);
13288 
13289                 dest = dynsym + e->dynindx * bed->s->sizeof_sym;
13290                 bed->s->swap_symbol_out (abfd, &sym, dest, 0);
13291               }
13292           }
13293     }
13294 
13295   /* We get the global symbols from the hash table.  */
13296   eoinfo.failed = false;
13297   eoinfo.localsyms = false;
13298   eoinfo.flinfo = &flinfo;
13299   bfd_hash_traverse (&info->hash->table, elf_link_output_extsym, &eoinfo);
13300   if (eoinfo.failed)
13301     {
13302       ret = false;
13303       goto return_local_hash_table;
13304     }
13305 
13306   /* If backend needs to output some symbols not present in the hash
13307      table, do it now.  */
13308   if (bed->elf_backend_output_arch_syms
13309       && (info->strip != strip_all || emit_relocs))
13310     {
13311       if (! ((*bed->elf_backend_output_arch_syms)
13312                (abfd, info, &flinfo, elf_link_output_symstrtab)))
13313           {
13314             ret = false;
13315             goto return_local_hash_table;
13316           }
13317     }
13318 
13319   /* Finalize the .strtab section.  */
13320   _bfd_elf_strtab_finalize (flinfo.symstrtab);
13321 
13322   /* Swap out the .strtab section. */
13323   if (!elf_link_swap_symbols_out (&flinfo))
13324     {
13325       ret = false;
13326       goto return_local_hash_table;
13327     }
13328 
13329   /* Now we know the size of the symtab section.  */
13330   if (bfd_get_symcount (abfd) > 0)
13331     {
13332       /* Finish up and write out the symbol string table (.strtab)
13333            section.  */
13334       Elf_Internal_Shdr *symstrtab_hdr = NULL;
13335       file_ptr off = symtab_hdr->sh_offset + symtab_hdr->sh_size;
13336 
13337       if (elf_symtab_shndx_list (abfd))
13338           {
13339             symtab_shndx_hdr = & elf_symtab_shndx_list (abfd)->hdr;
13340 
13341             if (symtab_shndx_hdr != NULL && symtab_shndx_hdr->sh_name != 0)
13342               {
13343                 symtab_shndx_hdr->sh_type = SHT_SYMTAB_SHNDX;
13344                 symtab_shndx_hdr->sh_entsize = sizeof (Elf_External_Sym_Shndx);
13345                 symtab_shndx_hdr->sh_addralign = sizeof (Elf_External_Sym_Shndx);
13346                 amt = bfd_get_symcount (abfd) * sizeof (Elf_External_Sym_Shndx);
13347                 symtab_shndx_hdr->sh_size = amt;
13348 
13349                 off = _bfd_elf_assign_file_position_for_section (symtab_shndx_hdr,
13350                                                                              off, true);
13351 
13352                 if (bfd_seek (abfd, symtab_shndx_hdr->sh_offset, SEEK_SET) != 0
13353                       || (bfd_write (flinfo.symshndxbuf, amt, abfd) != amt))
13354                     {
13355                       ret = false;
13356                       goto return_local_hash_table;
13357                     }
13358               }
13359           }
13360 
13361       symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
13362       /* sh_name was set in prep_headers.  */
13363       symstrtab_hdr->sh_type = SHT_STRTAB;
13364       symstrtab_hdr->sh_flags = bed->elf_strtab_flags;
13365       symstrtab_hdr->sh_addr = 0;
13366       symstrtab_hdr->sh_size = _bfd_elf_strtab_size (flinfo.symstrtab);
13367       symstrtab_hdr->sh_entsize = 0;
13368       symstrtab_hdr->sh_link = 0;
13369       symstrtab_hdr->sh_info = 0;
13370       /* sh_offset is set just below.  */
13371       symstrtab_hdr->sh_addralign = 1;
13372 
13373       off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr,
13374                                                                    off, true);
13375       elf_next_file_pos (abfd) = off;
13376 
13377       if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
13378             || ! _bfd_elf_strtab_emit (abfd, flinfo.symstrtab))
13379           {
13380             ret = false;
13381             goto return_local_hash_table;
13382           }
13383     }
13384 
13385   if (info->out_implib_bfd && !elf_output_implib (abfd, info))
13386     {
13387       _bfd_error_handler (_("%pB: failed to generate import library"),
13388                                 info->out_implib_bfd);
13389       ret = false;
13390       goto return_local_hash_table;
13391     }
13392 
13393   /* Adjust the relocs to have the correct symbol indices.  */
13394   for (o = abfd->sections; o != NULL; o = o->next)
13395     {
13396       struct bfd_elf_section_data *esdo = elf_section_data (o);
13397       bool sort;
13398 
13399       if ((o->flags & SEC_RELOC) == 0)
13400           continue;
13401 
13402       sort = bed->sort_relocs_p == NULL || (*bed->sort_relocs_p) (o);
13403       if (esdo->rel.hdr != NULL
13404             && !elf_link_adjust_relocs (abfd, o, &esdo->rel, sort, info))
13405           {
13406             ret = false;
13407             goto return_local_hash_table;
13408           }
13409       if (esdo->rela.hdr != NULL
13410             && !elf_link_adjust_relocs (abfd, o, &esdo->rela, sort, info))
13411           {
13412             ret = false;
13413             goto return_local_hash_table;
13414           }
13415 
13416       /* Set the reloc_count field to 0 to prevent write_relocs from
13417            trying to swap the relocs out itself.  */
13418       o->reloc_count = 0;
13419     }
13420 
13421   relativecount = 0;
13422   if (dynamic && info->combreloc && dynobj != NULL)
13423     relativecount = elf_link_sort_relocs (abfd, info, &reldyn);
13424 
13425   relr_entsize = 0;
13426   if (htab->srelrdyn != NULL
13427       && htab->srelrdyn->output_section != NULL
13428       && htab->srelrdyn->size != 0)
13429     {
13430       asection *s = htab->srelrdyn->output_section;
13431       relr_entsize = elf_section_data (s)->this_hdr.sh_entsize;
13432       if (relr_entsize == 0)
13433           {
13434             relr_entsize = bed->s->arch_size / 8;
13435             elf_section_data (s)->this_hdr.sh_entsize = relr_entsize;
13436           }
13437     }
13438 
13439   /* If we are linking against a dynamic object, or generating a
13440      shared library, finish up the dynamic linking information.  */
13441   if (dynamic)
13442     {
13443       bfd_byte *dyncon, *dynconend;
13444 
13445       /* Fix up .dynamic entries.  */
13446       o = htab->dynamic;
13447       BFD_ASSERT (o != NULL);
13448 
13449       dyncon = o->contents;
13450       dynconend = PTR_ADD (o->contents, o->size);
13451       for (; dyncon < dynconend; dyncon += bed->s->sizeof_dyn)
13452           {
13453             Elf_Internal_Dyn dyn;
13454             const char *name;
13455             unsigned int type;
13456             bfd_size_type sh_size;
13457             bfd_vma sh_addr;
13458 
13459             bed->s->swap_dyn_in (dynobj, dyncon, &dyn);
13460 
13461             switch (dyn.d_tag)
13462               {
13463               default:
13464                 continue;
13465               case DT_NULL:
13466                 if (relativecount != 0)
13467                     {
13468                       switch (elf_section_data (reldyn)->this_hdr.sh_type)
13469                         {
13470                         case SHT_REL: dyn.d_tag = DT_RELCOUNT; break;
13471                         case SHT_RELA: dyn.d_tag = DT_RELACOUNT; break;
13472                         }
13473                       if (dyn.d_tag != DT_NULL
13474                           && dynconend - dyncon >= bed->s->sizeof_dyn)
13475                         {
13476                           dyn.d_un.d_val = relativecount;
13477                           relativecount = 0;
13478                           break;
13479                         }
13480                       relativecount = 0;
13481                     }
13482                 if (relr_entsize != 0)
13483                     {
13484                       if (dynconend - dyncon >= 3 * bed->s->sizeof_dyn)
13485                         {
13486                           asection *s = htab->srelrdyn;
13487                           dyn.d_tag = DT_RELR;
13488                           dyn.d_un.d_ptr
13489                               = s->output_section->vma + s->output_offset;
13490                           bed->s->swap_dyn_out (dynobj, &dyn, dyncon);
13491                           dyncon += bed->s->sizeof_dyn;
13492 
13493                           dyn.d_tag = DT_RELRSZ;
13494                           dyn.d_un.d_val = s->size;
13495                           bed->s->swap_dyn_out (dynobj, &dyn, dyncon);
13496                           dyncon += bed->s->sizeof_dyn;
13497 
13498                           dyn.d_tag = DT_RELRENT;
13499                           dyn.d_un.d_val = relr_entsize;
13500                           relr_entsize = 0;
13501                           break;
13502                         }
13503                       relr_entsize = 0;
13504                     }
13505                 continue;
13506 
13507               case DT_INIT:
13508                 name = info->init_function;
13509                 goto get_sym;
13510               case DT_FINI:
13511                 name = info->fini_function;
13512               get_sym:
13513                 {
13514                     struct elf_link_hash_entry *h;
13515 
13516                     h = elf_link_hash_lookup (htab, name, false, false, true);
13517                     if (h != NULL
13518                         && (h->root.type == bfd_link_hash_defined
13519                               || h->root.type == bfd_link_hash_defweak))
13520                       {
13521                         dyn.d_un.d_ptr = h->root.u.def.value;
13522                         o = h->root.u.def.section;
13523                         if (o->output_section != NULL)
13524                           dyn.d_un.d_ptr += (o->output_section->vma
13525                                                    + o->output_offset);
13526                         else
13527                           {
13528                               /* The symbol is imported from another shared
13529                                  library and does not apply to this one.  */
13530                               dyn.d_un.d_ptr = 0;
13531                           }
13532                         break;
13533                       }
13534                 }
13535                 continue;
13536 
13537               case DT_PREINIT_ARRAYSZ:
13538                 name = ".preinit_array";
13539                 goto get_out_size;
13540               case DT_INIT_ARRAYSZ:
13541                 name = ".init_array";
13542                 goto get_out_size;
13543               case DT_FINI_ARRAYSZ:
13544                 name = ".fini_array";
13545               get_out_size:
13546                 o = bfd_get_section_by_name (abfd, name);
13547                 if (o == NULL)
13548                     {
13549                       _bfd_error_handler
13550                         (_("could not find section %s"), name);
13551                       goto error_return;
13552                     }
13553                 if (o->size == 0)
13554                     _bfd_error_handler
13555                       (_("warning: %s section has zero size"), name);
13556                 dyn.d_un.d_val = o->size;
13557                 break;
13558 
13559               case DT_PREINIT_ARRAY:
13560                 name = ".preinit_array";
13561                 goto get_out_vma;
13562               case DT_INIT_ARRAY:
13563                 name = ".init_array";
13564                 goto get_out_vma;
13565               case DT_FINI_ARRAY:
13566                 name = ".fini_array";
13567               get_out_vma:
13568                 o = bfd_get_section_by_name (abfd, name);
13569                 goto do_vma;
13570 
13571               case DT_HASH:
13572                 name = ".hash";
13573                 goto get_vma;
13574               case DT_GNU_HASH:
13575                 name = ".gnu.hash";
13576                 goto get_vma;
13577               case DT_STRTAB:
13578                 name = ".dynstr";
13579                 goto get_vma;
13580               case DT_SYMTAB:
13581                 name = ".dynsym";
13582                 goto get_vma;
13583               case DT_VERDEF:
13584                 name = ".gnu.version_d";
13585                 goto get_vma;
13586               case DT_VERNEED:
13587                 name = ".gnu.version_r";
13588                 goto get_vma;
13589               case DT_VERSYM:
13590                 name = ".gnu.version";
13591               get_vma:
13592                 o = bfd_get_linker_section (dynobj, name);
13593               do_vma:
13594                 if (o == NULL || bfd_is_abs_section (o->output_section))
13595                     {
13596                       _bfd_error_handler
13597                         (_("could not find section %s"), name);
13598                       goto error_return;
13599                     }
13600                 if (elf_section_data (o->output_section)->this_hdr.sh_type == SHT_NOTE)
13601                     {
13602                       _bfd_error_handler
13603                         (_("warning: section '%s' is being made into a note"), name);
13604                       bfd_set_error (bfd_error_nonrepresentable_section);
13605                       goto error_return;
13606                     }
13607                 dyn.d_un.d_ptr = o->output_section->vma + o->output_offset;
13608                 break;
13609 
13610               case DT_REL:
13611               case DT_RELA:
13612               case DT_RELSZ:
13613               case DT_RELASZ:
13614                 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
13615                     type = SHT_REL;
13616                 else
13617                     type = SHT_RELA;
13618                 sh_size = 0;
13619                 sh_addr = 0;
13620                 for (i = 1; i < elf_numsections (abfd); i++)
13621                     {
13622                       Elf_Internal_Shdr *hdr;
13623 
13624                       hdr = elf_elfsections (abfd)[i];
13625                       if (hdr->sh_type == type
13626                           && (hdr->sh_flags & SHF_ALLOC) != 0)
13627                         {
13628                           sh_size += hdr->sh_size;
13629                           if (sh_addr == 0
13630                                 || sh_addr > hdr->sh_addr)
13631                               sh_addr = hdr->sh_addr;
13632                         }
13633                     }
13634 
13635                 if (bed->dtrel_excludes_plt && htab->srelplt != NULL)
13636                     {
13637                       unsigned int opb = bfd_octets_per_byte (abfd, o);
13638 
13639                       /* Don't count procedure linkage table relocs in the
13640                          overall reloc count.  */
13641                       sh_size -= htab->srelplt->size;
13642                       if (sh_size == 0)
13643                         /* If the size is zero, make the address zero too.
13644                            This is to avoid a glibc bug.  If the backend
13645                            emits DT_RELA/DT_RELASZ even when DT_RELASZ is
13646                            zero, then we'll put DT_RELA at the end of
13647                            DT_JMPREL.  glibc will interpret the end of
13648                            DT_RELA matching the end of DT_JMPREL as the
13649                            case where DT_RELA includes DT_JMPREL, and for
13650                            LD_BIND_NOW will decide that processing DT_RELA
13651                            will process the PLT relocs too.  Net result:
13652                            No PLT relocs applied.  */
13653                         sh_addr = 0;
13654 
13655                       /* If .rela.plt is the first .rela section, exclude
13656                          it from DT_RELA.  */
13657                       else if (sh_addr == (htab->srelplt->output_section->vma
13658                                                + htab->srelplt->output_offset) * opb)
13659                         sh_addr += htab->srelplt->size;
13660                     }
13661 
13662                 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
13663                     dyn.d_un.d_val = sh_size;
13664                 else
13665                     dyn.d_un.d_ptr = sh_addr;
13666                 break;
13667               }
13668             bed->s->swap_dyn_out (dynobj, &dyn, dyncon);
13669           }
13670     }
13671 
13672   /* If we have created any dynamic sections, then output them.  */
13673   if (dynobj != NULL)
13674     {
13675       if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
13676           goto error_return;
13677 
13678       /* Check for DT_TEXTREL (late, in case the backend removes it).  */
13679       if (bfd_link_textrel_check (info)
13680             && (o = htab->dynamic) != NULL
13681             && o->size != 0)
13682           {
13683             bfd_byte *dyncon, *dynconend;
13684 
13685             dyncon = o->contents;
13686             dynconend = o->contents + o->size;
13687             for (; dyncon < dynconend; dyncon += bed->s->sizeof_dyn)
13688               {
13689                 Elf_Internal_Dyn dyn;
13690 
13691                 bed->s->swap_dyn_in (dynobj, dyncon, &dyn);
13692 
13693                 if (dyn.d_tag == DT_TEXTREL)
13694                     {
13695                       if (info->textrel_check == textrel_check_error)
13696                         info->callbacks->einfo
13697                           (_("%P%X: read-only segment has dynamic relocations\n"));
13698                       else if (bfd_link_dll (info))
13699                         info->callbacks->einfo
13700                           (_("%P: warning: creating DT_TEXTREL in a shared object\n"));
13701                       else if (bfd_link_pde (info))
13702                         info->callbacks->einfo
13703                           (_("%P: warning: creating DT_TEXTREL in a PDE\n"));
13704                       else
13705                         info->callbacks->einfo
13706                           (_("%P: warning: creating DT_TEXTREL in a PIE\n"));
13707                       break;
13708                     }
13709               }
13710           }
13711 
13712       for (o = dynobj->sections; o != NULL; o = o->next)
13713           {
13714             if ((o->flags & SEC_HAS_CONTENTS) == 0
13715                 || o->size == 0
13716                 || o->output_section == bfd_abs_section_ptr)
13717               continue;
13718             if ((o->flags & SEC_LINKER_CREATED) == 0)
13719               {
13720                 /* At this point, we are only interested in sections
13721                      created by _bfd_elf_link_create_dynamic_sections.  */
13722                 continue;
13723               }
13724             if (htab->stab_info.stabstr == o)
13725               continue;
13726             if (htab->eh_info.hdr_sec == o)
13727               continue;
13728             if (strcmp (o->name, ".dynstr") != 0)
13729               {
13730                 bfd_size_type octets = ((file_ptr) o->output_offset
13731                                               * bfd_octets_per_byte (abfd, o));
13732                 if (!bfd_set_section_contents (abfd, o->output_section,
13733                                                        o->contents, octets, o->size))
13734                     goto error_return;
13735               }
13736             else
13737               {
13738                 /* The contents of the .dynstr section are actually in a
13739                      stringtab.  */
13740                 file_ptr off;
13741 
13742                 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
13743                 if (bfd_seek (abfd, off, SEEK_SET) != 0
13744                       || !_bfd_elf_strtab_emit (abfd, htab->dynstr))
13745                     goto error_return;
13746               }
13747           }
13748     }
13749 
13750   if (!info->resolve_section_groups)
13751     {
13752       bool failed = false;
13753 
13754       BFD_ASSERT (bfd_link_relocatable (info));
13755       bfd_map_over_sections (abfd, bfd_elf_set_group_contents, &failed);
13756       if (failed)
13757           goto error_return;
13758     }
13759 
13760   /* If we have optimized stabs strings, output them.  */
13761   if (htab->stab_info.stabstr != NULL)
13762     {
13763       if (!_bfd_write_stab_strings (abfd, &htab->stab_info))
13764           goto error_return;
13765     }
13766 
13767   if (! _bfd_elf_write_section_eh_frame_hdr (abfd, info))
13768     goto error_return;
13769 
13770   if (! _bfd_elf_write_section_sframe (abfd, info))
13771     goto error_return;
13772 
13773   if (info->callbacks->emit_ctf)
13774       info->callbacks->emit_ctf ();
13775 
13776   elf_final_link_free (abfd, &flinfo);
13777 
13778   if (attr_section)
13779     {
13780       bfd_byte *contents = (bfd_byte *) bfd_malloc (attr_size);
13781       if (contents == NULL)
13782           {
13783             /* Bail out and fail.  */
13784             ret = false;
13785             goto return_local_hash_table;
13786           }
13787       bfd_elf_set_obj_attr_contents (abfd, contents, attr_size);
13788       bfd_set_section_contents (abfd, attr_section, contents, 0, attr_size);
13789       free (contents);
13790     }
13791 
13792  return_local_hash_table:
13793   if (info->unique_symbol)
13794     bfd_hash_table_free (&flinfo.local_hash_table);
13795   return ret;
13796 
13797  error_return:
13798   elf_final_link_free (abfd, &flinfo);
13799   ret = false;
13800   goto return_local_hash_table;
13801 }
13802 
13803 /* Initialize COOKIE for input bfd ABFD.  */
13804 
13805 static bool
init_reloc_cookie(struct elf_reloc_cookie * cookie,struct bfd_link_info * info,bfd * abfd,bool keep_memory)13806 init_reloc_cookie (struct elf_reloc_cookie *cookie,
13807                        struct bfd_link_info *info, bfd *abfd,
13808                        bool keep_memory)
13809 {
13810   Elf_Internal_Shdr *symtab_hdr;
13811   const struct elf_backend_data *bed;
13812 
13813   bed = get_elf_backend_data (abfd);
13814   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
13815 
13816   cookie->abfd = abfd;
13817   cookie->sym_hashes = elf_sym_hashes (abfd);
13818   cookie->bad_symtab = elf_bad_symtab (abfd);
13819   if (cookie->bad_symtab)
13820     {
13821       cookie->locsymcount = symtab_hdr->sh_size / bed->s->sizeof_sym;
13822       cookie->extsymoff = 0;
13823     }
13824   else
13825     {
13826       cookie->locsymcount = symtab_hdr->sh_info;
13827       cookie->extsymoff = symtab_hdr->sh_info;
13828     }
13829 
13830   if (bed->s->arch_size == 32)
13831     cookie->r_sym_shift = 8;
13832   else
13833     cookie->r_sym_shift = 32;
13834 
13835   cookie->locsyms = (Elf_Internal_Sym *) symtab_hdr->contents;
13836   if (cookie->locsyms == NULL && cookie->locsymcount != 0)
13837     {
13838       cookie->locsyms = bfd_elf_get_elf_syms (abfd, symtab_hdr,
13839                                                         cookie->locsymcount, 0,
13840                                                         NULL, NULL, NULL);
13841       if (cookie->locsyms == NULL)
13842           {
13843             info->callbacks->einfo (_("%P%X: can not read symbols: %E\n"));
13844             return false;
13845           }
13846       if (keep_memory || _bfd_elf_link_keep_memory (info))
13847           {
13848             symtab_hdr->contents = (bfd_byte *) cookie->locsyms;
13849             info->cache_size += (cookie->locsymcount
13850                                      * sizeof (Elf_External_Sym_Shndx));
13851           }
13852     }
13853   return true;
13854 }
13855 
13856 /* Free the memory allocated by init_reloc_cookie, if appropriate.  */
13857 
13858 static void
fini_reloc_cookie(struct elf_reloc_cookie * cookie,bfd * abfd)13859 fini_reloc_cookie (struct elf_reloc_cookie *cookie, bfd *abfd)
13860 {
13861   Elf_Internal_Shdr *symtab_hdr;
13862 
13863   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
13864   if (symtab_hdr->contents != (unsigned char *) cookie->locsyms)
13865     free (cookie->locsyms);
13866 }
13867 
13868 /* Initialize the relocation information in COOKIE for input section SEC
13869    of input bfd ABFD.  */
13870 
13871 static bool
init_reloc_cookie_rels(struct elf_reloc_cookie * cookie,struct bfd_link_info * info,bfd * abfd,asection * sec,bool keep_memory)13872 init_reloc_cookie_rels (struct elf_reloc_cookie *cookie,
13873                               struct bfd_link_info *info, bfd *abfd,
13874                               asection *sec, bool keep_memory)
13875 {
13876   if (sec->reloc_count == 0)
13877     {
13878       cookie->rels = NULL;
13879       cookie->relend = NULL;
13880     }
13881   else
13882     {
13883       cookie->rels = _bfd_elf_link_info_read_relocs
13884           (abfd, info, sec, NULL, NULL,
13885            keep_memory || _bfd_elf_link_keep_memory (info));
13886       if (cookie->rels == NULL)
13887           return false;
13888       cookie->rel = cookie->rels;
13889       cookie->relend = cookie->rels + sec->reloc_count;
13890     }
13891   cookie->rel = cookie->rels;
13892   return true;
13893 }
13894 
13895 /* Free the memory allocated by init_reloc_cookie_rels,
13896    if appropriate.  */
13897 
13898 static void
fini_reloc_cookie_rels(struct elf_reloc_cookie * cookie,asection * sec)13899 fini_reloc_cookie_rels (struct elf_reloc_cookie *cookie,
13900                               asection *sec)
13901 {
13902   if (elf_section_data (sec)->relocs != cookie->rels)
13903     free (cookie->rels);
13904 }
13905 
13906 /* Initialize the whole of COOKIE for input section SEC.  */
13907 
13908 static bool
init_reloc_cookie_for_section(struct elf_reloc_cookie * cookie,struct bfd_link_info * info,asection * sec,bool keep_memory)13909 init_reloc_cookie_for_section (struct elf_reloc_cookie *cookie,
13910                                      struct bfd_link_info *info,
13911                                      asection *sec, bool keep_memory)
13912 {
13913   if (!init_reloc_cookie (cookie, info, sec->owner, keep_memory))
13914     goto error1;
13915   if (!init_reloc_cookie_rels (cookie, info, sec->owner, sec,
13916                                      keep_memory))
13917     goto error2;
13918   return true;
13919 
13920  error2:
13921   fini_reloc_cookie (cookie, sec->owner);
13922  error1:
13923   return false;
13924 }
13925 
13926 /* Free the memory allocated by init_reloc_cookie_for_section,
13927    if appropriate.  */
13928 
13929 static void
fini_reloc_cookie_for_section(struct elf_reloc_cookie * cookie,asection * sec)13930 fini_reloc_cookie_for_section (struct elf_reloc_cookie *cookie,
13931                                      asection *sec)
13932 {
13933   fini_reloc_cookie_rels (cookie, sec);
13934   fini_reloc_cookie (cookie, sec->owner);
13935 }
13936 
13937 /* Garbage collect unused sections.  */
13938 
13939 /* Default gc_mark_hook.  */
13940 
13941 asection *
_bfd_elf_gc_mark_hook(asection * sec,struct bfd_link_info * info ATTRIBUTE_UNUSED,Elf_Internal_Rela * rel ATTRIBUTE_UNUSED,struct elf_link_hash_entry * h,Elf_Internal_Sym * sym)13942 _bfd_elf_gc_mark_hook (asection *sec,
13943                            struct bfd_link_info *info ATTRIBUTE_UNUSED,
13944                            Elf_Internal_Rela *rel ATTRIBUTE_UNUSED,
13945                            struct elf_link_hash_entry *h,
13946                            Elf_Internal_Sym *sym)
13947 {
13948   if (h != NULL)
13949     {
13950       switch (h->root.type)
13951           {
13952           case bfd_link_hash_defined:
13953           case bfd_link_hash_defweak:
13954             return h->root.u.def.section;
13955 
13956           case bfd_link_hash_common:
13957             return h->root.u.c.p->section;
13958 
13959           default:
13960             break;
13961           }
13962     }
13963   else
13964     return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
13965 
13966   return NULL;
13967 }
13968 
13969 /* Return the debug definition section.  */
13970 
13971 static asection *
elf_gc_mark_debug_section(asection * sec ATTRIBUTE_UNUSED,struct bfd_link_info * info ATTRIBUTE_UNUSED,Elf_Internal_Rela * rel ATTRIBUTE_UNUSED,struct elf_link_hash_entry * h,Elf_Internal_Sym * sym)13972 elf_gc_mark_debug_section (asection *sec ATTRIBUTE_UNUSED,
13973                                  struct bfd_link_info *info ATTRIBUTE_UNUSED,
13974                                  Elf_Internal_Rela *rel ATTRIBUTE_UNUSED,
13975                                  struct elf_link_hash_entry *h,
13976                                  Elf_Internal_Sym *sym)
13977 {
13978   if (h != NULL)
13979     {
13980       /* Return the global debug definition section.  */
13981       if ((h->root.type == bfd_link_hash_defined
13982              || h->root.type == bfd_link_hash_defweak)
13983             && (h->root.u.def.section->flags & SEC_DEBUGGING) != 0)
13984           return h->root.u.def.section;
13985     }
13986   else
13987     {
13988       /* Return the local debug definition section.  */
13989       asection *isec = bfd_section_from_elf_index (sec->owner,
13990                                                                sym->st_shndx);
13991       if (isec != NULL && (isec->flags & SEC_DEBUGGING) != 0)
13992           return isec;
13993     }
13994 
13995   return NULL;
13996 }
13997 
13998 /* COOKIE->rel describes a relocation against section SEC, which is
13999    a section we've decided to keep.  Return the section that contains
14000    the relocation symbol, or NULL if no section contains it.  */
14001 
14002 asection *
_bfd_elf_gc_mark_rsec(struct bfd_link_info * info,asection * sec,elf_gc_mark_hook_fn gc_mark_hook,struct elf_reloc_cookie * cookie,bool * start_stop)14003 _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
14004                            elf_gc_mark_hook_fn gc_mark_hook,
14005                            struct elf_reloc_cookie *cookie,
14006                            bool *start_stop)
14007 {
14008   unsigned long r_symndx;
14009   struct elf_link_hash_entry *h, *hw;
14010 
14011   r_symndx = cookie->rel->r_info >> cookie->r_sym_shift;
14012   if (r_symndx == STN_UNDEF)
14013     return NULL;
14014 
14015   if (r_symndx >= cookie->locsymcount
14016       || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
14017     {
14018       bool was_marked;
14019 
14020       h = cookie->sym_hashes[r_symndx - cookie->extsymoff];
14021       if (h == NULL)
14022           {
14023             info->callbacks->einfo (_("%F%P: corrupt input: %pB\n"),
14024                                           sec->owner);
14025             return NULL;
14026           }
14027       while (h->root.type == bfd_link_hash_indirect
14028                || h->root.type == bfd_link_hash_warning)
14029           h = (struct elf_link_hash_entry *) h->root.u.i.link;
14030 
14031       was_marked = h->mark;
14032       h->mark = 1;
14033       /* Keep all aliases of the symbol too.  If an object symbol
14034            needs to be copied into .dynbss then all of its aliases
14035            should be present as dynamic symbols, not just the one used
14036            on the copy relocation.  */
14037       hw = h;
14038       while (hw->is_weakalias)
14039           {
14040             hw = hw->u.alias;
14041             hw->mark = 1;
14042           }
14043 
14044       if (!was_marked && h->start_stop && !h->root.ldscript_def)
14045           {
14046             if (info->start_stop_gc)
14047               return NULL;
14048 
14049             /* To work around a glibc bug, mark XXX input sections
14050                when there is a reference to __start_XXX or __stop_XXX
14051                symbols.  */
14052             else if (start_stop != NULL)
14053               {
14054                 asection *s = h->u2.start_stop_section;
14055                 *start_stop = true;
14056                 return s;
14057               }
14058           }
14059 
14060       return (*gc_mark_hook) (sec, info, cookie->rel, h, NULL);
14061     }
14062 
14063   return (*gc_mark_hook) (sec, info, cookie->rel, NULL,
14064                                 &cookie->locsyms[r_symndx]);
14065 }
14066 
14067 /* COOKIE->rel describes a relocation against section SEC, which is
14068    a section we've decided to keep.  Mark the section that contains
14069    the relocation symbol.  */
14070 
14071 bool
_bfd_elf_gc_mark_reloc(struct bfd_link_info * info,asection * sec,elf_gc_mark_hook_fn gc_mark_hook,struct elf_reloc_cookie * cookie)14072 _bfd_elf_gc_mark_reloc (struct bfd_link_info *info,
14073                               asection *sec,
14074                               elf_gc_mark_hook_fn gc_mark_hook,
14075                               struct elf_reloc_cookie *cookie)
14076 {
14077   asection *rsec;
14078   bool start_stop = false;
14079 
14080   rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook, cookie, &start_stop);
14081   while (rsec != NULL)
14082     {
14083       if (!rsec->gc_mark)
14084           {
14085             if (bfd_get_flavour (rsec->owner) != bfd_target_elf_flavour
14086                 || (rsec->owner->flags & DYNAMIC) != 0)
14087               rsec->gc_mark = 1;
14088             else if (!_bfd_elf_gc_mark (info, rsec, gc_mark_hook))
14089               return false;
14090           }
14091       if (!start_stop)
14092           break;
14093       rsec = bfd_get_next_section_by_name (rsec->owner, rsec);
14094     }
14095   return true;
14096 }
14097 
14098 /* The mark phase of garbage collection.  For a given section, mark
14099    it and any sections in this section's group, and all the sections
14100    which define symbols to which it refers.  */
14101 
14102 bool
_bfd_elf_gc_mark(struct bfd_link_info * info,asection * sec,elf_gc_mark_hook_fn gc_mark_hook)14103 _bfd_elf_gc_mark (struct bfd_link_info *info,
14104                       asection *sec,
14105                       elf_gc_mark_hook_fn gc_mark_hook)
14106 {
14107   bool ret;
14108   asection *group_sec, *eh_frame;
14109 
14110   sec->gc_mark = 1;
14111 
14112   /* Mark all the sections in the group.  */
14113   group_sec = elf_section_data (sec)->next_in_group;
14114   if (group_sec && !group_sec->gc_mark)
14115     if (!_bfd_elf_gc_mark (info, group_sec, gc_mark_hook))
14116       return false;
14117 
14118   /* Look through the section relocs.  */
14119   ret = true;
14120   eh_frame = elf_eh_frame_section (sec->owner);
14121   if ((sec->flags & SEC_RELOC) != 0
14122       && sec->reloc_count > 0
14123       && sec != eh_frame)
14124     {
14125       struct elf_reloc_cookie cookie;
14126 
14127       if (!init_reloc_cookie_for_section (&cookie, info, sec, false))
14128           ret = false;
14129       else
14130           {
14131             for (; cookie.rel < cookie.relend; cookie.rel++)
14132               if (!_bfd_elf_gc_mark_reloc (info, sec, gc_mark_hook, &cookie))
14133                 {
14134                     ret = false;
14135                     break;
14136                 }
14137             fini_reloc_cookie_for_section (&cookie, sec);
14138           }
14139     }
14140 
14141   if (ret && eh_frame && elf_fde_list (sec))
14142     {
14143       struct elf_reloc_cookie cookie;
14144 
14145       /* NB: When --no-keep-memory is used, the symbol table and
14146            relocation info for eh_frame are freed after they are retrieved
14147            for each text section in the input object.  If an input object
14148            has many text sections, the same data is retrieved and freed
14149            many times which can take a very long time.  Always keep the
14150            symbol table and relocation info for eh_frame to avoid it.  */
14151       if (!init_reloc_cookie_for_section (&cookie, info, eh_frame,
14152                                                     true))
14153           ret = false;
14154       else
14155           {
14156             if (!_bfd_elf_gc_mark_fdes (info, sec, eh_frame,
14157                                               gc_mark_hook, &cookie))
14158               ret = false;
14159             fini_reloc_cookie_for_section (&cookie, eh_frame);
14160           }
14161     }
14162 
14163   eh_frame = elf_section_eh_frame_entry (sec);
14164   if (ret && eh_frame && !eh_frame->gc_mark)
14165     if (!_bfd_elf_gc_mark (info, eh_frame, gc_mark_hook))
14166       ret = false;
14167 
14168   return ret;
14169 }
14170 
14171 /* Scan and mark sections in a special or debug section group.  */
14172 
14173 static void
_bfd_elf_gc_mark_debug_special_section_group(asection * grp)14174 _bfd_elf_gc_mark_debug_special_section_group (asection *grp)
14175 {
14176   /* Point to first section of section group.  */
14177   asection *ssec;
14178   /* Used to iterate the section group.  */
14179   asection *msec;
14180 
14181   bool is_special_grp = true;
14182   bool is_debug_grp = true;
14183 
14184   /* First scan to see if group contains any section other than debug
14185      and special section.  */
14186   ssec = msec = elf_next_in_group (grp);
14187   do
14188     {
14189       if ((msec->flags & SEC_DEBUGGING) == 0)
14190           is_debug_grp = false;
14191 
14192       if ((msec->flags & (SEC_ALLOC | SEC_LOAD | SEC_RELOC)) != 0)
14193           is_special_grp = false;
14194 
14195       msec = elf_next_in_group (msec);
14196     }
14197   while (msec != ssec);
14198 
14199   /* If this is a pure debug section group or pure special section group,
14200      keep all sections in this group.  */
14201   if (is_debug_grp || is_special_grp)
14202     {
14203       do
14204           {
14205             msec->gc_mark = 1;
14206             msec = elf_next_in_group (msec);
14207           }
14208       while (msec != ssec);
14209     }
14210 }
14211 
14212 /* Keep debug and special sections.  */
14213 
14214 bool
_bfd_elf_gc_mark_extra_sections(struct bfd_link_info * info,elf_gc_mark_hook_fn mark_hook)14215 _bfd_elf_gc_mark_extra_sections (struct bfd_link_info *info,
14216                                          elf_gc_mark_hook_fn mark_hook)
14217 {
14218   bfd *ibfd;
14219 
14220   for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
14221     {
14222       asection *isec;
14223       bool some_kept;
14224       bool debug_frag_seen;
14225       bool has_kept_debug_info;
14226 
14227       if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
14228           continue;
14229       isec = ibfd->sections;
14230       if (isec == NULL || isec->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
14231           continue;
14232 
14233       /* Ensure all linker created sections are kept,
14234            see if any other section is already marked,
14235            and note if we have any fragmented debug sections.  */
14236       debug_frag_seen = some_kept = has_kept_debug_info = false;
14237       for (isec = ibfd->sections; isec != NULL; isec = isec->next)
14238           {
14239             if ((isec->flags & SEC_LINKER_CREATED) != 0)
14240               isec->gc_mark = 1;
14241             else if (isec->gc_mark
14242                        && (isec->flags & SEC_ALLOC) != 0
14243                        && elf_section_type (isec) != SHT_NOTE)
14244               some_kept = true;
14245             else
14246               {
14247                 /* Since all sections, except for backend specific ones,
14248                      have been garbage collected, call mark_hook on this
14249                      section if any of its linked-to sections is marked.  */
14250                 asection *linked_to_sec;
14251                 for (linked_to_sec = elf_linked_to_section (isec);
14252                        linked_to_sec != NULL && !linked_to_sec->linker_mark;
14253                        linked_to_sec = elf_linked_to_section (linked_to_sec))
14254                     {
14255                       if (linked_to_sec->gc_mark)
14256                         {
14257                           if (!_bfd_elf_gc_mark (info, isec, mark_hook))
14258                               return false;
14259                           break;
14260                         }
14261                       linked_to_sec->linker_mark = 1;
14262                     }
14263                 for (linked_to_sec = elf_linked_to_section (isec);
14264                        linked_to_sec != NULL && linked_to_sec->linker_mark;
14265                        linked_to_sec = elf_linked_to_section (linked_to_sec))
14266                     linked_to_sec->linker_mark = 0;
14267               }
14268 
14269             if (!debug_frag_seen
14270                 && (isec->flags & SEC_DEBUGGING)
14271                 && startswith (isec->name, ".debug_line."))
14272               debug_frag_seen = true;
14273             else if (strcmp (bfd_section_name (isec),
14274                                  "__patchable_function_entries") == 0
14275                        && elf_linked_to_section (isec) == NULL)
14276                 info->callbacks->einfo (_("%F%P: %pB(%pA): error: "
14277                                                   "need linked-to section "
14278                                                   "for --gc-sections\n"),
14279                                               isec->owner, isec);
14280           }
14281 
14282       /* If no non-note alloc section in this file will be kept, then
14283            we can toss out the debug and special sections.  */
14284       if (!some_kept)
14285           continue;
14286 
14287       /* Keep debug and special sections like .comment when they are
14288            not part of a group.  Also keep section groups that contain
14289            just debug sections or special sections.  NB: Sections with
14290            linked-to section has been handled above.  */
14291       for (isec = ibfd->sections; isec != NULL; isec = isec->next)
14292           {
14293             if ((isec->flags & SEC_GROUP) != 0)
14294               _bfd_elf_gc_mark_debug_special_section_group (isec);
14295             else if (((isec->flags & SEC_DEBUGGING) != 0
14296                         || (isec->flags & (SEC_ALLOC | SEC_LOAD | SEC_RELOC)) == 0)
14297                        && elf_next_in_group (isec) == NULL
14298                        && elf_linked_to_section (isec) == NULL)
14299               isec->gc_mark = 1;
14300             if (isec->gc_mark && (isec->flags & SEC_DEBUGGING) != 0)
14301               has_kept_debug_info = true;
14302           }
14303 
14304       /* Look for CODE sections which are going to be discarded,
14305            and find and discard any fragmented debug sections which
14306            are associated with that code section.  */
14307       if (debug_frag_seen)
14308           for (isec = ibfd->sections; isec != NULL; isec = isec->next)
14309             if ((isec->flags & SEC_CODE) != 0
14310                 && isec->gc_mark == 0)
14311               {
14312                 unsigned int ilen;
14313                 asection *dsec;
14314 
14315                 ilen = strlen (isec->name);
14316 
14317                 /* Association is determined by the name of the debug
14318                      section containing the name of the code section as
14319                      a suffix.  For example .debug_line.text.foo is a
14320                      debug section associated with .text.foo.  */
14321                 for (dsec = ibfd->sections; dsec != NULL; dsec = dsec->next)
14322                     {
14323                       unsigned int dlen;
14324 
14325                       if (dsec->gc_mark == 0
14326                           || (dsec->flags & SEC_DEBUGGING) == 0)
14327                         continue;
14328 
14329                       dlen = strlen (dsec->name);
14330 
14331                       if (dlen > ilen
14332                           && strncmp (dsec->name + (dlen - ilen),
14333                                           isec->name, ilen) == 0)
14334                         dsec->gc_mark = 0;
14335                     }
14336             }
14337 
14338       /* Mark debug sections referenced by kept debug sections.  */
14339       if (has_kept_debug_info)
14340           for (isec = ibfd->sections; isec != NULL; isec = isec->next)
14341             if (isec->gc_mark
14342                 && (isec->flags & SEC_DEBUGGING) != 0)
14343               if (!_bfd_elf_gc_mark (info, isec,
14344                                            elf_gc_mark_debug_section))
14345                 return false;
14346     }
14347   return true;
14348 }
14349 
14350 static bool
elf_gc_sweep(bfd * abfd,struct bfd_link_info * info)14351 elf_gc_sweep (bfd *abfd, struct bfd_link_info *info)
14352 {
14353   bfd *sub;
14354   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
14355 
14356   for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
14357     {
14358       asection *o;
14359 
14360       if (bfd_get_flavour (sub) != bfd_target_elf_flavour
14361             || elf_object_id (sub) != elf_hash_table_id (elf_hash_table (info))
14362             || !(*bed->relocs_compatible) (sub->xvec, abfd->xvec))
14363           continue;
14364       o = sub->sections;
14365       if (o == NULL || o->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
14366           continue;
14367 
14368       for (o = sub->sections; o != NULL; o = o->next)
14369           {
14370             /* When any section in a section group is kept, we keep all
14371                sections in the section group.  If the first member of
14372                the section group is excluded, we will also exclude the
14373                group section.  */
14374             if (o->flags & SEC_GROUP)
14375               {
14376                 asection *first = elf_next_in_group (o);
14377                 o->gc_mark = first->gc_mark;
14378               }
14379 
14380             if (o->gc_mark)
14381               continue;
14382 
14383             /* Skip sweeping sections already excluded.  */
14384             if (o->flags & SEC_EXCLUDE)
14385               continue;
14386 
14387             /* Since this is early in the link process, it is simple
14388                to remove a section from the output.  */
14389             o->flags |= SEC_EXCLUDE;
14390 
14391             if (info->print_gc_sections && o->size != 0)
14392               /* xgettext:c-format */
14393               _bfd_error_handler (_("removing unused section '%pA' in file '%pB'"),
14394                                         o, sub);
14395           }
14396     }
14397 
14398   return true;
14399 }
14400 
14401 /* Propagate collected vtable information.  This is called through
14402    elf_link_hash_traverse.  */
14403 
14404 static bool
elf_gc_propagate_vtable_entries_used(struct elf_link_hash_entry * h,void * okp)14405 elf_gc_propagate_vtable_entries_used (struct elf_link_hash_entry *h, void *okp)
14406 {
14407   /* Those that are not vtables.  */
14408   if (h->start_stop
14409       || h->u2.vtable == NULL
14410       || h->u2.vtable->parent == NULL)
14411     return true;
14412 
14413   /* Those vtables that do not have parents, we cannot merge.  */
14414   if (h->u2.vtable->parent == (struct elf_link_hash_entry *) -1)
14415     return true;
14416 
14417   /* If we've already been done, exit.  */
14418   if (h->u2.vtable->used && h->u2.vtable->used[-1])
14419     return true;
14420 
14421   /* Make sure the parent's table is up to date.  */
14422   elf_gc_propagate_vtable_entries_used (h->u2.vtable->parent, okp);
14423 
14424   if (h->u2.vtable->used == NULL)
14425     {
14426       /* None of this table's entries were referenced.  Re-use the
14427            parent's table.  */
14428       h->u2.vtable->used = h->u2.vtable->parent->u2.vtable->used;
14429       h->u2.vtable->size = h->u2.vtable->parent->u2.vtable->size;
14430     }
14431   else
14432     {
14433       size_t n;
14434       bool *cu, *pu;
14435 
14436       /* Or the parent's entries into ours.  */
14437       cu = h->u2.vtable->used;
14438       cu[-1] = true;
14439       pu = h->u2.vtable->parent->u2.vtable->used;
14440       if (pu != NULL)
14441           {
14442             const struct elf_backend_data *bed;
14443             unsigned int log_file_align;
14444 
14445             bed = get_elf_backend_data (h->root.u.def.section->owner);
14446             log_file_align = bed->s->log_file_align;
14447             n = h->u2.vtable->parent->u2.vtable->size >> log_file_align;
14448             while (n--)
14449               {
14450                 if (*pu)
14451                     *cu = true;
14452                 pu++;
14453                 cu++;
14454               }
14455           }
14456     }
14457 
14458   return true;
14459 }
14460 
14461 struct link_info_ok
14462 {
14463   struct bfd_link_info *info;
14464   bool ok;
14465 };
14466 
14467 static bool
elf_gc_smash_unused_vtentry_relocs(struct elf_link_hash_entry * h,void * ptr)14468 elf_gc_smash_unused_vtentry_relocs (struct elf_link_hash_entry *h,
14469                                             void *ptr)
14470 {
14471   asection *sec;
14472   bfd_vma hstart, hend;
14473   Elf_Internal_Rela *relstart, *relend, *rel;
14474   const struct elf_backend_data *bed;
14475   unsigned int log_file_align;
14476   struct link_info_ok *info = (struct link_info_ok *) ptr;
14477 
14478   /* Take care of both those symbols that do not describe vtables as
14479      well as those that are not loaded.  */
14480   if (h->start_stop
14481       || h->u2.vtable == NULL
14482       || h->u2.vtable->parent == NULL)
14483     return true;
14484 
14485   BFD_ASSERT (h->root.type == bfd_link_hash_defined
14486                 || h->root.type == bfd_link_hash_defweak);
14487 
14488   sec = h->root.u.def.section;
14489   hstart = h->root.u.def.value;
14490   hend = hstart + h->size;
14491 
14492   relstart = _bfd_elf_link_info_read_relocs (sec->owner, info->info,
14493                                                        sec, NULL, NULL, true);
14494   if (!relstart)
14495     return info->ok = false;
14496   bed = get_elf_backend_data (sec->owner);
14497   log_file_align = bed->s->log_file_align;
14498 
14499   relend = relstart + sec->reloc_count;
14500 
14501   for (rel = relstart; rel < relend; ++rel)
14502     if (rel->r_offset >= hstart && rel->r_offset < hend)
14503       {
14504           /* If the entry is in use, do nothing.  */
14505           if (h->u2.vtable->used
14506               && (rel->r_offset - hstart) < h->u2.vtable->size)
14507             {
14508               bfd_vma entry = (rel->r_offset - hstart) >> log_file_align;
14509               if (h->u2.vtable->used[entry])
14510                 continue;
14511             }
14512           /* Otherwise, kill it.  */
14513           rel->r_offset = rel->r_info = rel->r_addend = 0;
14514       }
14515 
14516   return true;
14517 }
14518 
14519 /* Mark sections containing dynamically referenced symbols.  When
14520    building shared libraries, we must assume that any visible symbol is
14521    referenced.  */
14522 
14523 bool
bfd_elf_gc_mark_dynamic_ref_symbol(struct elf_link_hash_entry * h,void * inf)14524 bfd_elf_gc_mark_dynamic_ref_symbol (struct elf_link_hash_entry *h, void *inf)
14525 {
14526   struct bfd_link_info *info = (struct bfd_link_info *) inf;
14527   struct bfd_elf_dynamic_list *d = info->dynamic_list;
14528 
14529   if ((h->root.type == bfd_link_hash_defined
14530        || h->root.type == bfd_link_hash_defweak)
14531       && (!h->start_stop
14532             || h->root.ldscript_def
14533             || !info->start_stop_gc)
14534       && ((h->ref_dynamic && !h->forced_local)
14535             || ((h->def_regular || ELF_COMMON_DEF_P (h))
14536                 && ELF_ST_VISIBILITY (h->other) != STV_INTERNAL
14537                 && ELF_ST_VISIBILITY (h->other) != STV_HIDDEN
14538                 && (!bfd_link_executable (info)
14539                       || info->gc_keep_exported
14540                       || info->export_dynamic
14541                       || (h->dynamic
14542                           && d != NULL
14543                           && (*d->match) (&d->head, NULL, h->root.root.string)))
14544                 && (h->versioned >= versioned
14545                       || !bfd_hide_sym_by_version (info->version_info,
14546                                                          h->root.root.string)))))
14547     h->root.u.def.section->flags |= SEC_KEEP;
14548 
14549   return true;
14550 }
14551 
14552 /* Keep all sections containing symbols undefined on the command-line,
14553    and the section containing the entry symbol.  */
14554 
14555 void
_bfd_elf_gc_keep(struct bfd_link_info * info)14556 _bfd_elf_gc_keep (struct bfd_link_info *info)
14557 {
14558   struct bfd_sym_chain *sym;
14559 
14560   for (sym = info->gc_sym_list; sym != NULL; sym = sym->next)
14561     {
14562       struct elf_link_hash_entry *h;
14563 
14564       h = elf_link_hash_lookup (elf_hash_table (info), sym->name,
14565                                         false, false, false);
14566 
14567       if (h != NULL
14568             && (h->root.type == bfd_link_hash_defined
14569                 || h->root.type == bfd_link_hash_defweak)
14570             && !bfd_is_const_section (h->root.u.def.section))
14571           h->root.u.def.section->flags |= SEC_KEEP;
14572     }
14573 }
14574 
14575 bool
bfd_elf_parse_eh_frame_entries(bfd * abfd ATTRIBUTE_UNUSED,struct bfd_link_info * info)14576 bfd_elf_parse_eh_frame_entries (bfd *abfd ATTRIBUTE_UNUSED,
14577                                         struct bfd_link_info *info)
14578 {
14579   bfd *ibfd = info->input_bfds;
14580 
14581   for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
14582     {
14583       asection *sec;
14584       struct elf_reloc_cookie cookie;
14585 
14586       if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
14587           continue;
14588       sec = ibfd->sections;
14589       if (sec == NULL || sec->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
14590           continue;
14591 
14592       if (!init_reloc_cookie (&cookie, info, ibfd, false))
14593           return false;
14594 
14595       for (sec = ibfd->sections; sec; sec = sec->next)
14596           {
14597             if (startswith (bfd_section_name (sec), ".eh_frame_entry")
14598                 && init_reloc_cookie_rels (&cookie, info, ibfd, sec,
14599                                                    false))
14600               {
14601                 _bfd_elf_parse_eh_frame_entry (info, sec, &cookie);
14602                 fini_reloc_cookie_rels (&cookie, sec);
14603               }
14604           }
14605     }
14606   return true;
14607 }
14608 
14609 /* Do mark and sweep of unused sections.  */
14610 
14611 bool
bfd_elf_gc_sections(bfd * abfd,struct bfd_link_info * info)14612 bfd_elf_gc_sections (bfd *abfd, struct bfd_link_info *info)
14613 {
14614   bool ok = true;
14615   bfd *sub;
14616   elf_gc_mark_hook_fn gc_mark_hook;
14617   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
14618   struct elf_link_hash_table *htab;
14619   struct link_info_ok info_ok;
14620 
14621   if (!bed->can_gc_sections
14622       || !is_elf_hash_table (info->hash))
14623     {
14624       _bfd_error_handler(_("warning: gc-sections option ignored"));
14625       return true;
14626     }
14627 
14628   bed->gc_keep (info);
14629   htab = elf_hash_table (info);
14630 
14631   /* Try to parse each bfd's .eh_frame section.  Point elf_eh_frame_section
14632      at the .eh_frame section if we can mark the FDEs individually.  */
14633   for (sub = info->input_bfds;
14634        info->eh_frame_hdr_type != COMPACT_EH_HDR && sub != NULL;
14635        sub = sub->link.next)
14636     {
14637       asection *sec;
14638       struct elf_reloc_cookie cookie;
14639 
14640       sec = sub->sections;
14641       if (sec == NULL || sec->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
14642           continue;
14643       sec = bfd_get_section_by_name (sub, ".eh_frame");
14644       while (sec && init_reloc_cookie_for_section (&cookie, info, sec,
14645                                                                false))
14646           {
14647             _bfd_elf_parse_eh_frame (sub, info, sec, &cookie);
14648             if (elf_section_data (sec)->sec_info
14649                 && (sec->flags & SEC_LINKER_CREATED) == 0)
14650               elf_eh_frame_section (sub) = sec;
14651             fini_reloc_cookie_for_section (&cookie, sec);
14652             sec = bfd_get_next_section_by_name (NULL, sec);
14653           }
14654     }
14655 
14656   /* Apply transitive closure to the vtable entry usage info.  */
14657   elf_link_hash_traverse (htab, elf_gc_propagate_vtable_entries_used, &ok);
14658   if (!ok)
14659     return false;
14660 
14661   /* Kill the vtable relocations that were not used.  */
14662   info_ok.info = info;
14663   info_ok.ok = true;
14664   elf_link_hash_traverse (htab, elf_gc_smash_unused_vtentry_relocs, &info_ok);
14665   if (!info_ok.ok)
14666     return false;
14667 
14668   /* Mark dynamically referenced symbols.  */
14669   if (htab->dynamic_sections_created || info->gc_keep_exported)
14670     elf_link_hash_traverse (htab, bed->gc_mark_dynamic_ref, info);
14671 
14672   /* Grovel through relocs to find out who stays ...  */
14673   gc_mark_hook = bed->gc_mark_hook;
14674   for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
14675     {
14676       asection *o;
14677 
14678       if (bfd_get_flavour (sub) != bfd_target_elf_flavour
14679             || elf_object_id (sub) != elf_hash_table_id (htab)
14680             || !(*bed->relocs_compatible) (sub->xvec, abfd->xvec))
14681           continue;
14682 
14683       o = sub->sections;
14684       if (o == NULL || o->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
14685           continue;
14686 
14687       /* Start at sections marked with SEC_KEEP (ref _bfd_elf_gc_keep).
14688            Also treat note sections as a root, if the section is not part
14689            of a group.  We must keep all PREINIT_ARRAY, INIT_ARRAY as
14690            well as FINI_ARRAY sections for ld -r.  */
14691       for (o = sub->sections; o != NULL; o = o->next)
14692           if (!o->gc_mark
14693               && (o->flags & SEC_EXCLUDE) == 0
14694               && ((o->flags & SEC_KEEP) != 0
14695                     || (bfd_link_relocatable (info)
14696                         && ((elf_section_data (o)->this_hdr.sh_type
14697                                == SHT_PREINIT_ARRAY)
14698                               || (elf_section_data (o)->this_hdr.sh_type
14699                                   == SHT_INIT_ARRAY)
14700                               || (elf_section_data (o)->this_hdr.sh_type
14701                                   == SHT_FINI_ARRAY)))
14702                     || (elf_section_data (o)->this_hdr.sh_type == SHT_NOTE
14703                         && elf_next_in_group (o) == NULL
14704                         && elf_linked_to_section (o) == NULL)
14705                     || ((elf_tdata (sub)->has_gnu_osabi & elf_gnu_osabi_retain)
14706                         && (elf_section_flags (o) & SHF_GNU_RETAIN))))
14707             {
14708               if (!_bfd_elf_gc_mark (info, o, gc_mark_hook))
14709                 return false;
14710             }
14711     }
14712 
14713   /* Allow the backend to mark additional target specific sections.  */
14714   bed->gc_mark_extra_sections (info, gc_mark_hook);
14715 
14716   /* ... and mark SEC_EXCLUDE for those that go.  */
14717   return elf_gc_sweep (abfd, info);
14718 }
14719 
14720 /* Called from check_relocs to record the existence of a VTINHERIT reloc.  */
14721 
14722 bool
bfd_elf_gc_record_vtinherit(bfd * abfd,asection * sec,struct elf_link_hash_entry * h,bfd_vma offset)14723 bfd_elf_gc_record_vtinherit (bfd *abfd,
14724                                    asection *sec,
14725                                    struct elf_link_hash_entry *h,
14726                                    bfd_vma offset)
14727 {
14728   struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
14729   struct elf_link_hash_entry **search, *child;
14730   size_t extsymcount;
14731   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
14732 
14733   /* The sh_info field of the symtab header tells us where the
14734      external symbols start.  We don't care about the local symbols at
14735      this point.  */
14736   extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size / bed->s->sizeof_sym;
14737   if (!elf_bad_symtab (abfd))
14738     extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
14739 
14740   sym_hashes = elf_sym_hashes (abfd);
14741   sym_hashes_end = PTR_ADD (sym_hashes, extsymcount);
14742 
14743   /* Hunt down the child symbol, which is in this section at the same
14744      offset as the relocation.  */
14745   for (search = sym_hashes; search != sym_hashes_end; ++search)
14746     {
14747       if ((child = *search) != NULL
14748             && (child->root.type == bfd_link_hash_defined
14749                 || child->root.type == bfd_link_hash_defweak)
14750             && child->root.u.def.section == sec
14751             && child->root.u.def.value == offset)
14752           goto win;
14753     }
14754 
14755   /* xgettext:c-format */
14756   _bfd_error_handler (_("%pB: %pA+%#" PRIx64 ": no symbol found for INHERIT"),
14757                           abfd, sec, (uint64_t) offset);
14758   bfd_set_error (bfd_error_invalid_operation);
14759   return false;
14760 
14761  win:
14762   if (!child->u2.vtable)
14763     {
14764       child->u2.vtable = ((struct elf_link_virtual_table_entry *)
14765                                 bfd_zalloc (abfd, sizeof (*child->u2.vtable)));
14766       if (!child->u2.vtable)
14767           return false;
14768     }
14769   if (!h)
14770     {
14771       /* This *should* only be the absolute section.  It could potentially
14772            be that someone has defined a non-global vtable though, which
14773            would be bad.  It isn't worth paging in the local symbols to be
14774            sure though; that case should simply be handled by the assembler.  */
14775 
14776       child->u2.vtable->parent = (struct elf_link_hash_entry *) -1;
14777     }
14778   else
14779     child->u2.vtable->parent = h;
14780 
14781   return true;
14782 }
14783 
14784 /* Called from check_relocs to record the existence of a VTENTRY reloc.  */
14785 
14786 bool
bfd_elf_gc_record_vtentry(bfd * abfd,asection * sec,struct elf_link_hash_entry * h,bfd_vma addend)14787 bfd_elf_gc_record_vtentry (bfd *abfd, asection *sec,
14788                                  struct elf_link_hash_entry *h,
14789                                  bfd_vma addend)
14790 {
14791   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
14792   unsigned int log_file_align = bed->s->log_file_align;
14793 
14794   if (!h)
14795     {
14796       /* xgettext:c-format */
14797       _bfd_error_handler (_("%pB: section '%pA': corrupt VTENTRY entry"),
14798                                 abfd, sec);
14799       bfd_set_error (bfd_error_bad_value);
14800       return false;
14801     }
14802 
14803   if (!h->u2.vtable)
14804     {
14805       h->u2.vtable = ((struct elf_link_virtual_table_entry *)
14806                           bfd_zalloc (abfd, sizeof (*h->u2.vtable)));
14807       if (!h->u2.vtable)
14808           return false;
14809     }
14810 
14811   if (addend >= h->u2.vtable->size)
14812     {
14813       size_t size, bytes, file_align;
14814       bool *ptr = h->u2.vtable->used;
14815 
14816       /* While the symbol is undefined, we have to be prepared to handle
14817            a zero size.  */
14818       file_align = 1 << log_file_align;
14819       if (h->root.type == bfd_link_hash_undefined)
14820           size = addend + file_align;
14821       else
14822           {
14823             size = h->size;
14824             if (addend >= size)
14825               {
14826                 /* Oops!  We've got a reference past the defined end of
14827                      the table.  This is probably a bug -- shall we warn?  */
14828                 size = addend + file_align;
14829               }
14830           }
14831       size = (size + file_align - 1) & -file_align;
14832 
14833       /* Allocate one extra entry for use as a "done" flag for the
14834            consolidation pass.  */
14835       bytes = ((size >> log_file_align) + 1) * sizeof (bool);
14836 
14837       if (ptr)
14838           {
14839             ptr = (bool *) bfd_realloc (ptr - 1, bytes);
14840 
14841             if (ptr != NULL)
14842               {
14843                 size_t oldbytes;
14844 
14845                 oldbytes = (((h->u2.vtable->size >> log_file_align) + 1)
14846                                 * sizeof (bool));
14847                 memset (((char *) ptr) + oldbytes, 0, bytes - oldbytes);
14848               }
14849           }
14850       else
14851           ptr = (bool *) bfd_zmalloc (bytes);
14852 
14853       if (ptr == NULL)
14854           return false;
14855 
14856       /* And arrange for that done flag to be at index -1.  */
14857       h->u2.vtable->used = ptr + 1;
14858       h->u2.vtable->size = size;
14859     }
14860 
14861   h->u2.vtable->used[addend >> log_file_align] = true;
14862 
14863   return true;
14864 }
14865 
14866 /* Map an ELF section header flag to its corresponding string.  */
14867 typedef struct
14868 {
14869   char *flag_name;
14870   flagword flag_value;
14871 } elf_flags_to_name_table;
14872 
14873 static const elf_flags_to_name_table elf_flags_to_names [] =
14874 {
14875   { "SHF_WRITE", SHF_WRITE },
14876   { "SHF_ALLOC", SHF_ALLOC },
14877   { "SHF_EXECINSTR", SHF_EXECINSTR },
14878   { "SHF_MERGE", SHF_MERGE },
14879   { "SHF_STRINGS", SHF_STRINGS },
14880   { "SHF_INFO_LINK", SHF_INFO_LINK},
14881   { "SHF_LINK_ORDER", SHF_LINK_ORDER},
14882   { "SHF_OS_NONCONFORMING", SHF_OS_NONCONFORMING},
14883   { "SHF_GROUP", SHF_GROUP },
14884   { "SHF_TLS", SHF_TLS },
14885   { "SHF_MASKOS", SHF_MASKOS },
14886   { "SHF_EXCLUDE", SHF_EXCLUDE },
14887 };
14888 
14889 /* Returns TRUE if the section is to be included, otherwise FALSE.  */
14890 bool
bfd_elf_lookup_section_flags(struct bfd_link_info * info,struct flag_info * flaginfo,asection * section)14891 bfd_elf_lookup_section_flags (struct bfd_link_info *info,
14892                                     struct flag_info *flaginfo,
14893                                     asection *section)
14894 {
14895   const bfd_vma sh_flags = elf_section_flags (section);
14896 
14897   if (!flaginfo->flags_initialized)
14898     {
14899       bfd *obfd = info->output_bfd;
14900       const struct elf_backend_data *bed = get_elf_backend_data (obfd);
14901       struct flag_info_list *tf = flaginfo->flag_list;
14902       int with_hex = 0;
14903       int without_hex = 0;
14904 
14905       for (tf = flaginfo->flag_list; tf != NULL; tf = tf->next)
14906           {
14907             unsigned i;
14908             flagword (*lookup) (char *);
14909 
14910             lookup = bed->elf_backend_lookup_section_flags_hook;
14911             if (lookup != NULL)
14912               {
14913                 flagword hexval = (*lookup) ((char *) tf->name);
14914 
14915                 if (hexval != 0)
14916                     {
14917                       if (tf->with == with_flags)
14918                         with_hex |= hexval;
14919                       else if (tf->with == without_flags)
14920                         without_hex |= hexval;
14921                       tf->valid = true;
14922                       continue;
14923                     }
14924               }
14925             for (i = 0; i < ARRAY_SIZE (elf_flags_to_names); ++i)
14926               {
14927                 if (strcmp (tf->name, elf_flags_to_names[i].flag_name) == 0)
14928                     {
14929                       if (tf->with == with_flags)
14930                         with_hex |= elf_flags_to_names[i].flag_value;
14931                       else if (tf->with == without_flags)
14932                         without_hex |= elf_flags_to_names[i].flag_value;
14933                       tf->valid = true;
14934                       break;
14935                     }
14936               }
14937             if (!tf->valid)
14938               {
14939                 info->callbacks->einfo
14940                     (_("unrecognized INPUT_SECTION_FLAG %s\n"), tf->name);
14941                 return false;
14942               }
14943           }
14944       flaginfo->flags_initialized = true;
14945       flaginfo->only_with_flags |= with_hex;
14946       flaginfo->not_with_flags |= without_hex;
14947     }
14948 
14949   if ((flaginfo->only_with_flags & sh_flags) != flaginfo->only_with_flags)
14950     return false;
14951 
14952   if ((flaginfo->not_with_flags & sh_flags) != 0)
14953     return false;
14954 
14955   return true;
14956 }
14957 
14958 struct alloc_got_off_arg {
14959   bfd_vma gotoff;
14960   struct bfd_link_info *info;
14961 };
14962 
14963 /* We need a special top-level link routine to convert got reference counts
14964    to real got offsets.  */
14965 
14966 static bool
elf_gc_allocate_got_offsets(struct elf_link_hash_entry * h,void * arg)14967 elf_gc_allocate_got_offsets (struct elf_link_hash_entry *h, void *arg)
14968 {
14969   struct alloc_got_off_arg *gofarg = (struct alloc_got_off_arg *) arg;
14970   bfd *obfd = gofarg->info->output_bfd;
14971   const struct elf_backend_data *bed = get_elf_backend_data (obfd);
14972 
14973   if (h->got.refcount > 0)
14974     {
14975       h->got.offset = gofarg->gotoff;
14976       gofarg->gotoff += bed->got_elt_size (obfd, gofarg->info, h, NULL, 0);
14977     }
14978   else
14979     h->got.offset = (bfd_vma) -1;
14980 
14981   return true;
14982 }
14983 
14984 /* And an accompanying bit to work out final got entry offsets once
14985    we're done.  Should be called from final_link.  */
14986 
14987 bool
bfd_elf_gc_common_finalize_got_offsets(bfd * abfd,struct bfd_link_info * info)14988 bfd_elf_gc_common_finalize_got_offsets (bfd *abfd,
14989                                                   struct bfd_link_info *info)
14990 {
14991   bfd *i;
14992   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
14993   bfd_vma gotoff;
14994   struct alloc_got_off_arg gofarg;
14995 
14996   BFD_ASSERT (abfd == info->output_bfd);
14997 
14998   if (! is_elf_hash_table (info->hash))
14999     return false;
15000 
15001   /* The GOT offset is relative to the .got section, but the GOT header is
15002      put into the .got.plt section, if the backend uses it.  */
15003   if (bed->want_got_plt)
15004     gotoff = 0;
15005   else
15006     gotoff = bed->got_header_size;
15007 
15008   /* Do the local .got entries first.  */
15009   for (i = info->input_bfds; i; i = i->link.next)
15010     {
15011       bfd_signed_vma *local_got;
15012       size_t j, locsymcount;
15013       Elf_Internal_Shdr *symtab_hdr;
15014 
15015       if (bfd_get_flavour (i) != bfd_target_elf_flavour)
15016           continue;
15017 
15018       local_got = elf_local_got_refcounts (i);
15019       if (!local_got)
15020           continue;
15021 
15022       symtab_hdr = &elf_tdata (i)->symtab_hdr;
15023       if (elf_bad_symtab (i))
15024           locsymcount = symtab_hdr->sh_size / bed->s->sizeof_sym;
15025       else
15026           locsymcount = symtab_hdr->sh_info;
15027 
15028       for (j = 0; j < locsymcount; ++j)
15029           {
15030             if (local_got[j] > 0)
15031               {
15032                 local_got[j] = gotoff;
15033                 gotoff += bed->got_elt_size (abfd, info, NULL, i, j);
15034               }
15035             else
15036               local_got[j] = (bfd_vma) -1;
15037           }
15038     }
15039 
15040   /* Then the global .got entries.  .plt refcounts are handled by
15041      adjust_dynamic_symbol  */
15042   gofarg.gotoff = gotoff;
15043   gofarg.info = info;
15044   elf_link_hash_traverse (elf_hash_table (info),
15045                                 elf_gc_allocate_got_offsets,
15046                                 &gofarg);
15047   return true;
15048 }
15049 
15050 /* Many folk need no more in the way of final link than this, once
15051    got entry reference counting is enabled.  */
15052 
15053 bool
bfd_elf_gc_common_final_link(bfd * abfd,struct bfd_link_info * info)15054 bfd_elf_gc_common_final_link (bfd *abfd, struct bfd_link_info *info)
15055 {
15056   if (!bfd_elf_gc_common_finalize_got_offsets (abfd, info))
15057     return false;
15058 
15059   /* Invoke the regular ELF backend linker to do all the work.  */
15060   return bfd_elf_final_link (abfd, info);
15061 }
15062 
15063 bool
bfd_elf_reloc_symbol_deleted_p(bfd_vma offset,void * cookie)15064 bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
15065 {
15066   struct elf_reloc_cookie *rcookie = (struct elf_reloc_cookie *) cookie;
15067 
15068   if (rcookie->bad_symtab)
15069     rcookie->rel = rcookie->rels;
15070 
15071   for (; rcookie->rel < rcookie->relend; rcookie->rel++)
15072     {
15073       unsigned long r_symndx;
15074 
15075       if (! rcookie->bad_symtab)
15076           if (rcookie->rel->r_offset > offset)
15077             return false;
15078       if (rcookie->rel->r_offset != offset)
15079           continue;
15080 
15081       r_symndx = rcookie->rel->r_info >> rcookie->r_sym_shift;
15082       if (r_symndx == STN_UNDEF)
15083           return true;
15084 
15085       if (r_symndx >= rcookie->locsymcount
15086             || ELF_ST_BIND (rcookie->locsyms[r_symndx].st_info) != STB_LOCAL)
15087           {
15088             struct elf_link_hash_entry *h;
15089 
15090             h = rcookie->sym_hashes[r_symndx - rcookie->extsymoff];
15091 
15092             while (h->root.type == bfd_link_hash_indirect
15093                      || h->root.type == bfd_link_hash_warning)
15094               h = (struct elf_link_hash_entry *) h->root.u.i.link;
15095 
15096             if ((h->root.type == bfd_link_hash_defined
15097                  || h->root.type == bfd_link_hash_defweak)
15098                 && (h->root.u.def.section->owner != rcookie->abfd
15099                       || h->root.u.def.section->kept_section != NULL
15100                       || discarded_section (h->root.u.def.section)))
15101               return true;
15102           }
15103       else
15104           {
15105             /* It's not a relocation against a global symbol,
15106                but it could be a relocation against a local
15107                symbol for a discarded section.  */
15108             asection *isec;
15109             Elf_Internal_Sym *isym;
15110 
15111             /* Need to: get the symbol; get the section.  */
15112             isym = &rcookie->locsyms[r_symndx];
15113             isec = bfd_section_from_elf_index (rcookie->abfd, isym->st_shndx);
15114             if (isec != NULL
15115                 && (isec->kept_section != NULL
15116                       || discarded_section (isec)))
15117               return true;
15118           }
15119       return false;
15120     }
15121   return false;
15122 }
15123 
15124 /* Discard unneeded references to discarded sections.
15125    Returns -1 on error, 1 if any section's size was changed, 0 if
15126    nothing changed.  This function assumes that the relocations are in
15127    sorted order, which is true for all known assemblers.  */
15128 
15129 int
bfd_elf_discard_info(bfd * output_bfd,struct bfd_link_info * info)15130 bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info)
15131 {
15132   struct elf_reloc_cookie cookie;
15133   asection *o;
15134   bfd *abfd;
15135   int changed = 0;
15136 
15137   if (info->traditional_format
15138       || !is_elf_hash_table (info->hash))
15139     return 0;
15140 
15141   o = bfd_get_section_by_name (output_bfd, ".stab");
15142   if (o != NULL)
15143     {
15144       asection *i;
15145 
15146       for (i = o->map_head.s; i != NULL; i = i->map_head.s)
15147           {
15148             if (i->size == 0
15149                 || i->reloc_count == 0
15150                 || i->sec_info_type != SEC_INFO_TYPE_STABS)
15151               continue;
15152 
15153             abfd = i->owner;
15154             if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
15155               continue;
15156 
15157             if (!init_reloc_cookie_for_section (&cookie, info, i, false))
15158               return -1;
15159 
15160             if (_bfd_discard_section_stabs (abfd, i,
15161                                                     elf_section_data (i)->sec_info,
15162                                                     bfd_elf_reloc_symbol_deleted_p,
15163                                                     &cookie))
15164               changed = 1;
15165 
15166             fini_reloc_cookie_for_section (&cookie, i);
15167           }
15168     }
15169 
15170   o = NULL;
15171   if (info->eh_frame_hdr_type != COMPACT_EH_HDR)
15172     o = bfd_get_section_by_name (output_bfd, ".eh_frame");
15173   if (o != NULL)
15174     {
15175       asection *i;
15176       int eh_changed = 0;
15177       unsigned int eh_alignment;  /* Octets.  */
15178 
15179       for (i = o->map_head.s; i != NULL; i = i->map_head.s)
15180           {
15181             if (i->size == 0)
15182               continue;
15183 
15184             abfd = i->owner;
15185             if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
15186               continue;
15187 
15188             if (!init_reloc_cookie_for_section (&cookie, info, i, false))
15189               return -1;
15190 
15191             _bfd_elf_parse_eh_frame (abfd, info, i, &cookie);
15192             if (_bfd_elf_discard_section_eh_frame (abfd, info, i,
15193                                                              bfd_elf_reloc_symbol_deleted_p,
15194                                                              &cookie))
15195               {
15196                 eh_changed = 1;
15197                 if (i->size != i->rawsize)
15198                     changed = 1;
15199               }
15200 
15201             fini_reloc_cookie_for_section (&cookie, i);
15202           }
15203 
15204       eh_alignment = ((1 << o->alignment_power)
15205                           * bfd_octets_per_byte (output_bfd, o));
15206       /* Skip over zero terminator, and prevent empty sections from
15207            adding alignment padding at the end.  */
15208       for (i = o->map_tail.s; i != NULL; i = i->map_tail.s)
15209           if (i->size == 0)
15210             i->flags |= SEC_EXCLUDE;
15211           else if (i->size > 4)
15212             break;
15213       /* The last non-empty eh_frame section doesn't need padding.  */
15214       if (i != NULL)
15215           i = i->map_tail.s;
15216       /* Any prior sections must pad the last FDE out to the output
15217            section alignment.  Otherwise we might have zero padding
15218            between sections, which would be seen as a terminator.  */
15219       for (; i != NULL; i = i->map_tail.s)
15220           if (i->size == 4)
15221             /* All but the last zero terminator should have been removed.  */
15222             BFD_FAIL ();
15223           else
15224             {
15225               bfd_size_type size
15226                 = (i->size + eh_alignment - 1) & -eh_alignment;
15227               if (i->size != size)
15228                 {
15229                     i->size = size;
15230                     changed = 1;
15231                     eh_changed = 1;
15232                 }
15233             }
15234       if (eh_changed)
15235           elf_link_hash_traverse (elf_hash_table (info),
15236                                         _bfd_elf_adjust_eh_frame_global_symbol, NULL);
15237     }
15238 
15239   o = bfd_get_section_by_name (output_bfd, ".sframe");
15240   if (o != NULL)
15241     {
15242       asection *i;
15243 
15244       for (i = o->map_head.s; i != NULL; i = i->map_head.s)
15245           {
15246             if (i->size == 0)
15247               continue;
15248 
15249             abfd = i->owner;
15250             if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
15251               continue;
15252 
15253             if (!init_reloc_cookie_for_section (&cookie, info, i, false))
15254               return -1;
15255 
15256             if (_bfd_elf_parse_sframe (abfd, info, i, &cookie))
15257               {
15258                 if (_bfd_elf_discard_section_sframe (i,
15259                                                                bfd_elf_reloc_symbol_deleted_p,
15260                                                                &cookie))
15261                     {
15262                       if (i->size != i->rawsize)
15263                         changed = 1;
15264                     }
15265               }
15266             fini_reloc_cookie_for_section (&cookie, i);
15267           }
15268       /* Update the reference to the output .sframe section.  Used to
15269            determine later if PT_GNU_SFRAME segment is to be generated.  */
15270       if (!_bfd_elf_set_section_sframe (output_bfd, info))
15271           return -1;
15272     }
15273 
15274   for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
15275     {
15276       const struct elf_backend_data *bed;
15277       asection *s;
15278 
15279       if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
15280           continue;
15281       s = abfd->sections;
15282       if (s == NULL || s->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
15283           continue;
15284 
15285       bed = get_elf_backend_data (abfd);
15286 
15287       if (bed->elf_backend_discard_info != NULL)
15288           {
15289             if (!init_reloc_cookie (&cookie, info, abfd, false))
15290               return -1;
15291 
15292             if ((*bed->elf_backend_discard_info) (abfd, &cookie, info))
15293               changed = 1;
15294 
15295             fini_reloc_cookie (&cookie, abfd);
15296           }
15297     }
15298 
15299   if (info->eh_frame_hdr_type == COMPACT_EH_HDR)
15300     _bfd_elf_end_eh_frame_parsing (info);
15301 
15302   if (info->eh_frame_hdr_type
15303       && !bfd_link_relocatable (info)
15304       && _bfd_elf_discard_section_eh_frame_hdr (info))
15305     changed = 1;
15306 
15307   return changed;
15308 }
15309 
15310 bool
_bfd_elf_section_already_linked(bfd * abfd,asection * sec,struct bfd_link_info * info)15311 _bfd_elf_section_already_linked (bfd *abfd,
15312                                          asection *sec,
15313                                          struct bfd_link_info *info)
15314 {
15315   flagword flags;
15316   const char *name, *key;
15317   struct bfd_section_already_linked *l;
15318   struct bfd_section_already_linked_hash_entry *already_linked_list;
15319 
15320   if (sec->output_section == bfd_abs_section_ptr)
15321     return false;
15322 
15323   flags = sec->flags;
15324 
15325   /* Return if it isn't a linkonce section.  A comdat group section
15326      also has SEC_LINK_ONCE set.  */
15327   if ((flags & SEC_LINK_ONCE) == 0)
15328     return false;
15329 
15330   /* Don't put group member sections on our list of already linked
15331      sections.  They are handled as a group via their group section.  */
15332   if (elf_sec_group (sec) != NULL)
15333     return false;
15334 
15335   /* For a SHT_GROUP section, use the group signature as the key.  */
15336   name = sec->name;
15337   if ((flags & SEC_GROUP) != 0
15338       && elf_next_in_group (sec) != NULL
15339       && elf_group_name (elf_next_in_group (sec)) != NULL)
15340     key = elf_group_name (elf_next_in_group (sec));
15341   else
15342     {
15343       /* Otherwise we should have a .gnu.linkonce.<type>.<key> section.  */
15344       if (startswith (name, ".gnu.linkonce.")
15345             && (key = strchr (name + sizeof (".gnu.linkonce.") - 1, '.')) != NULL)
15346           key++;
15347       else
15348           /* Must be a user linkonce section that doesn't follow gcc's
15349              naming convention.  In this case we won't be matching
15350              single member groups.  */
15351           key = name;
15352     }
15353 
15354   already_linked_list = bfd_section_already_linked_table_lookup (key);
15355 
15356   for (l = already_linked_list->entry; l != NULL; l = l->next)
15357     {
15358       /* We may have 2 different types of sections on the list: group
15359            sections with a signature of <key> (<key> is some string),
15360            and linkonce sections named .gnu.linkonce.<type>.<key>.
15361            Match like sections.  LTO plugin sections are an exception.
15362            They are always named .gnu.linkonce.t.<key> and match either
15363            type of section.  */
15364       if (((flags & SEC_GROUP) == (l->sec->flags & SEC_GROUP)
15365              && ((flags & SEC_GROUP) != 0
15366                  || strcmp (name, l->sec->name) == 0))
15367             || (l->sec->owner->flags & BFD_PLUGIN) != 0
15368             || (sec->owner->flags & BFD_PLUGIN) != 0)
15369           {
15370             /* The section has already been linked.  See if we should
15371                issue a warning.  */
15372             if (!_bfd_handle_already_linked (sec, l, info))
15373               return false;
15374 
15375             if (flags & SEC_GROUP)
15376               {
15377                 asection *first = elf_next_in_group (sec);
15378                 asection *s = first;
15379 
15380                 while (s != NULL)
15381                     {
15382                       s->output_section = bfd_abs_section_ptr;
15383                       /* Record which group discards it.  */
15384                       s->kept_section = l->sec;
15385                       s = elf_next_in_group (s);
15386                       /* These lists are circular.  */
15387                       if (s == first)
15388                         break;
15389                     }
15390               }
15391 
15392             return true;
15393           }
15394     }
15395 
15396   /* A single member comdat group section may be discarded by a
15397      linkonce section and vice versa.  */
15398   if ((flags & SEC_GROUP) != 0)
15399     {
15400       asection *first = elf_next_in_group (sec);
15401 
15402       if (first != NULL && elf_next_in_group (first) == first)
15403           /* Check this single member group against linkonce sections.  */
15404           for (l = already_linked_list->entry; l != NULL; l = l->next)
15405             if ((l->sec->flags & SEC_GROUP) == 0
15406                 && bfd_elf_match_symbols_in_sections (l->sec, first, info))
15407               {
15408                 first->output_section = bfd_abs_section_ptr;
15409                 first->kept_section = l->sec;
15410                 sec->output_section = bfd_abs_section_ptr;
15411                 break;
15412               }
15413     }
15414   else
15415     /* Check this linkonce section against single member groups.  */
15416     for (l = already_linked_list->entry; l != NULL; l = l->next)
15417       if (l->sec->flags & SEC_GROUP)
15418           {
15419             asection *first = elf_next_in_group (l->sec);
15420 
15421             if (first != NULL
15422                 && elf_next_in_group (first) == first
15423                 && bfd_elf_match_symbols_in_sections (first, sec, info))
15424               {
15425                 sec->output_section = bfd_abs_section_ptr;
15426                 sec->kept_section = first;
15427                 break;
15428               }
15429           }
15430 
15431   /* Do not complain on unresolved relocations in `.gnu.linkonce.r.F'
15432      referencing its discarded `.gnu.linkonce.t.F' counterpart - g++-3.4
15433      specific as g++-4.x is using COMDAT groups (without the `.gnu.linkonce'
15434      prefix) instead.  `.gnu.linkonce.r.*' were the `.rodata' part of its
15435      matching `.gnu.linkonce.t.*'.  If `.gnu.linkonce.r.F' is not discarded
15436      but its `.gnu.linkonce.t.F' is discarded means we chose one-only
15437      `.gnu.linkonce.t.F' section from a different bfd not requiring any
15438      `.gnu.linkonce.r.F'.  Thus `.gnu.linkonce.r.F' should be discarded.
15439      The reverse order cannot happen as there is never a bfd with only the
15440      `.gnu.linkonce.r.F' section.  The order of sections in a bfd does not
15441      matter as here were are looking only for cross-bfd sections.  */
15442 
15443   if ((flags & SEC_GROUP) == 0 && startswith (name, ".gnu.linkonce.r."))
15444     for (l = already_linked_list->entry; l != NULL; l = l->next)
15445       if ((l->sec->flags & SEC_GROUP) == 0
15446             && startswith (l->sec->name, ".gnu.linkonce.t."))
15447           {
15448             if (abfd != l->sec->owner)
15449               sec->output_section = bfd_abs_section_ptr;
15450             break;
15451           }
15452 
15453   /* This is the first section with this name.  Record it.  */
15454   if (!bfd_section_already_linked_table_insert (already_linked_list, sec))
15455     info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
15456   return sec->output_section == bfd_abs_section_ptr;
15457 }
15458 
15459 bool
_bfd_elf_common_definition(Elf_Internal_Sym * sym)15460 _bfd_elf_common_definition (Elf_Internal_Sym *sym)
15461 {
15462   return sym->st_shndx == SHN_COMMON;
15463 }
15464 
15465 unsigned int
_bfd_elf_common_section_index(asection * sec ATTRIBUTE_UNUSED)15466 _bfd_elf_common_section_index (asection *sec ATTRIBUTE_UNUSED)
15467 {
15468   return SHN_COMMON;
15469 }
15470 
15471 asection *
_bfd_elf_common_section(asection * sec ATTRIBUTE_UNUSED)15472 _bfd_elf_common_section (asection *sec ATTRIBUTE_UNUSED)
15473 {
15474   return bfd_com_section_ptr;
15475 }
15476 
15477 bfd_vma
_bfd_elf_default_got_elt_size(bfd * abfd,struct bfd_link_info * info ATTRIBUTE_UNUSED,struct elf_link_hash_entry * h ATTRIBUTE_UNUSED,bfd * ibfd ATTRIBUTE_UNUSED,unsigned long symndx ATTRIBUTE_UNUSED)15478 _bfd_elf_default_got_elt_size (bfd *abfd,
15479                                      struct bfd_link_info *info ATTRIBUTE_UNUSED,
15480                                      struct elf_link_hash_entry *h ATTRIBUTE_UNUSED,
15481                                      bfd *ibfd ATTRIBUTE_UNUSED,
15482                                      unsigned long symndx ATTRIBUTE_UNUSED)
15483 {
15484   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
15485   return bed->s->arch_size / 8;
15486 }
15487 
15488 /* Routines to support the creation of dynamic relocs.  */
15489 
15490 /* Returns the name of the dynamic reloc section associated with SEC.  */
15491 
15492 static const char *
get_dynamic_reloc_section_name(bfd * abfd,asection * sec,bool is_rela)15493 get_dynamic_reloc_section_name (bfd *       abfd,
15494                                         asection *  sec,
15495                                         bool is_rela)
15496 {
15497   char *name;
15498   const char *old_name = bfd_section_name (sec);
15499   const char *prefix = is_rela ? ".rela" : ".rel";
15500 
15501   if (old_name == NULL)
15502     return NULL;
15503 
15504   name = bfd_alloc (abfd, strlen (prefix) + strlen (old_name) + 1);
15505   sprintf (name, "%s%s", prefix, old_name);
15506 
15507   return name;
15508 }
15509 
15510 /* Returns the dynamic reloc section associated with SEC.
15511    If necessary compute the name of the dynamic reloc section based
15512    on SEC's name (looked up in ABFD's string table) and the setting
15513    of IS_RELA.  */
15514 
15515 asection *
_bfd_elf_get_dynamic_reloc_section(bfd * abfd,asection * sec,bool is_rela)15516 _bfd_elf_get_dynamic_reloc_section (bfd *abfd,
15517                                             asection *sec,
15518                                             bool is_rela)
15519 {
15520   asection *reloc_sec = elf_section_data (sec)->sreloc;
15521 
15522   if (reloc_sec == NULL)
15523     {
15524       const char *name = get_dynamic_reloc_section_name (abfd, sec, is_rela);
15525 
15526       if (name != NULL)
15527           {
15528             reloc_sec = bfd_get_linker_section (abfd, name);
15529 
15530             if (reloc_sec != NULL)
15531               elf_section_data (sec)->sreloc = reloc_sec;
15532           }
15533     }
15534 
15535   return reloc_sec;
15536 }
15537 
15538 /* Returns the dynamic reloc section associated with SEC.  If the
15539    section does not exist it is created and attached to the DYNOBJ
15540    bfd and stored in the SRELOC field of SEC's elf_section_data
15541    structure.
15542 
15543    ALIGNMENT is the alignment for the newly created section and
15544    IS_RELA defines whether the name should be .rela.<SEC's name>
15545    or .rel.<SEC's name>.  The section name is looked up in the
15546    string table associated with ABFD.  */
15547 
15548 asection *
_bfd_elf_make_dynamic_reloc_section(asection * sec,bfd * dynobj,unsigned int alignment,bfd * abfd,bool is_rela)15549 _bfd_elf_make_dynamic_reloc_section (asection *sec,
15550                                              bfd *dynobj,
15551                                              unsigned int alignment,
15552                                              bfd *abfd,
15553                                              bool is_rela)
15554 {
15555   asection * reloc_sec = elf_section_data (sec)->sreloc;
15556 
15557   if (reloc_sec == NULL)
15558     {
15559       const char * name = get_dynamic_reloc_section_name (abfd, sec, is_rela);
15560 
15561       if (name == NULL)
15562           return NULL;
15563 
15564       reloc_sec = bfd_get_linker_section (dynobj, name);
15565 
15566       if (reloc_sec == NULL)
15567           {
15568             flagword flags = (SEC_HAS_CONTENTS | SEC_READONLY
15569                                   | SEC_IN_MEMORY | SEC_LINKER_CREATED);
15570             if ((sec->flags & SEC_ALLOC) != 0)
15571               flags |= SEC_ALLOC | SEC_LOAD;
15572 
15573             reloc_sec = bfd_make_section_anyway_with_flags (dynobj, name, flags);
15574             if (reloc_sec != NULL)
15575               {
15576                 /* _bfd_elf_get_sec_type_attr chooses a section type by
15577                      name.  Override as it may be wrong, eg. for a user
15578                      section named "auto" we'll get ".relauto" which is
15579                      seen to be a .rela section.  */
15580                 elf_section_type (reloc_sec) = is_rela ? SHT_RELA : SHT_REL;
15581                 if (!bfd_set_section_alignment (reloc_sec, alignment))
15582                     reloc_sec = NULL;
15583               }
15584           }
15585 
15586       elf_section_data (sec)->sreloc = reloc_sec;
15587     }
15588 
15589   return reloc_sec;
15590 }
15591 
15592 /* Copy the ELF symbol type and other attributes for a linker script
15593    assignment from HSRC to HDEST.  Generally this should be treated as
15594    if we found a strong non-dynamic definition for HDEST (except that
15595    ld ignores multiple definition errors).  */
15596 void
_bfd_elf_copy_link_hash_symbol_type(bfd * abfd,struct bfd_link_hash_entry * hdest,struct bfd_link_hash_entry * hsrc)15597 _bfd_elf_copy_link_hash_symbol_type (bfd *abfd,
15598                                              struct bfd_link_hash_entry *hdest,
15599                                              struct bfd_link_hash_entry *hsrc)
15600 {
15601   struct elf_link_hash_entry *ehdest = (struct elf_link_hash_entry *) hdest;
15602   struct elf_link_hash_entry *ehsrc = (struct elf_link_hash_entry *) hsrc;
15603   Elf_Internal_Sym isym;
15604 
15605   ehdest->type = ehsrc->type;
15606   ehdest->target_internal = ehsrc->target_internal;
15607 
15608   isym.st_other = ehsrc->other;
15609   elf_merge_st_other (abfd, ehdest, isym.st_other, NULL, true, false);
15610 }
15611 
15612 /* Append a RELA relocation REL to section S in BFD.  */
15613 
15614 void
elf_append_rela(bfd * abfd,asection * s,Elf_Internal_Rela * rel)15615 elf_append_rela (bfd *abfd, asection *s, Elf_Internal_Rela *rel)
15616 {
15617   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
15618   bfd_byte *loc = s->contents + (s->reloc_count++ * bed->s->sizeof_rela);
15619   BFD_ASSERT (loc + bed->s->sizeof_rela <= s->contents + s->size);
15620   bed->s->swap_reloca_out (abfd, rel, loc);
15621 }
15622 
15623 /* Append a REL relocation REL to section S in BFD.  */
15624 
15625 void
elf_append_rel(bfd * abfd,asection * s,Elf_Internal_Rela * rel)15626 elf_append_rel (bfd *abfd, asection *s, Elf_Internal_Rela *rel)
15627 {
15628   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
15629   bfd_byte *loc = s->contents + (s->reloc_count++ * bed->s->sizeof_rel);
15630   BFD_ASSERT (loc + bed->s->sizeof_rel <= s->contents + s->size);
15631   bed->s->swap_reloc_out (abfd, rel, loc);
15632 }
15633 
15634 /* Define __start, __stop, .startof. or .sizeof. symbol.  */
15635 
15636 struct bfd_link_hash_entry *
bfd_elf_define_start_stop(struct bfd_link_info * info,const char * symbol,asection * sec)15637 bfd_elf_define_start_stop (struct bfd_link_info *info,
15638                                  const char *symbol, asection *sec)
15639 {
15640   struct elf_link_hash_entry *h;
15641 
15642   h = elf_link_hash_lookup (elf_hash_table (info), symbol,
15643                                   false, false, true);
15644   /* NB: Common symbols will be turned into definition later.  */
15645   if (h != NULL
15646       && !h->root.ldscript_def
15647       && (h->root.type == bfd_link_hash_undefined
15648             || h->root.type == bfd_link_hash_undefweak
15649             || ((h->ref_regular || h->def_dynamic)
15650                 && !h->def_regular
15651                 && h->root.type != bfd_link_hash_common)))
15652     {
15653       bool was_dynamic = h->ref_dynamic || h->def_dynamic;
15654       h->verinfo.verdef = NULL;
15655       h->root.type = bfd_link_hash_defined;
15656       h->root.u.def.section = sec;
15657       h->root.u.def.value = 0;
15658       h->def_regular = 1;
15659       h->def_dynamic = 0;
15660       h->start_stop = 1;
15661       h->u2.start_stop_section = sec;
15662       if (symbol[0] == '.')
15663           {
15664             /* .startof. and .sizeof. symbols are local.  */
15665             const struct elf_backend_data *bed;
15666             bed = get_elf_backend_data (info->output_bfd);
15667             (*bed->elf_backend_hide_symbol) (info, h, true);
15668           }
15669       else
15670           {
15671             if (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
15672               h->other = ((h->other & ~ELF_ST_VISIBILITY (-1))
15673                               | info->start_stop_visibility);
15674             if (was_dynamic)
15675               bfd_elf_link_record_dynamic_symbol (info, h);
15676           }
15677       return &h->root;
15678     }
15679   return NULL;
15680 }
15681 
15682 /* Find dynamic relocs for H that apply to read-only sections.  */
15683 
15684 asection *
_bfd_elf_readonly_dynrelocs(struct elf_link_hash_entry * h)15685 _bfd_elf_readonly_dynrelocs (struct elf_link_hash_entry *h)
15686 {
15687   struct elf_dyn_relocs *p;
15688 
15689   for (p = h->dyn_relocs; p != NULL; p = p->next)
15690     {
15691       asection *s = p->sec->output_section;
15692 
15693       if (s != NULL && (s->flags & SEC_READONLY) != 0)
15694           return p->sec;
15695     }
15696   return NULL;
15697 }
15698 
15699 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
15700    read-only sections.  */
15701 
15702 bool
_bfd_elf_maybe_set_textrel(struct elf_link_hash_entry * h,void * inf)15703 _bfd_elf_maybe_set_textrel (struct elf_link_hash_entry *h, void *inf)
15704 {
15705   asection *sec;
15706 
15707   if (h->root.type == bfd_link_hash_indirect)
15708     return true;
15709 
15710   sec = _bfd_elf_readonly_dynrelocs (h);
15711   if (sec != NULL)
15712     {
15713       struct bfd_link_info *info = (struct bfd_link_info *) inf;
15714 
15715       info->flags |= DF_TEXTREL;
15716       /* xgettext:c-format */
15717       info->callbacks->minfo (_("%pB: dynamic relocation against `%pT' "
15718                                         "in read-only section `%pA'\n"),
15719                                     sec->owner, h->root.root.string, sec);
15720 
15721       if (bfd_link_textrel_check (info))
15722           /* xgettext:c-format */
15723           info->callbacks->einfo (_("%P: %pB: warning: relocation against `%s' "
15724                                           "in read-only section `%pA'\n"),
15725                                         sec->owner, h->root.root.string, sec);
15726 
15727       /* Not an error, just cut short the traversal.  */
15728       return false;
15729     }
15730   return true;
15731 }
15732 
15733 /* Add dynamic tags.  */
15734 
15735 bool
_bfd_elf_add_dynamic_tags(bfd * output_bfd,struct bfd_link_info * info,bool need_dynamic_reloc)15736 _bfd_elf_add_dynamic_tags (bfd *output_bfd, struct bfd_link_info *info,
15737                                  bool need_dynamic_reloc)
15738 {
15739   struct elf_link_hash_table *htab = elf_hash_table (info);
15740 
15741   if (htab->dynamic_sections_created)
15742     {
15743       /* Add some entries to the .dynamic section.  We fill in the
15744            values later, in finish_dynamic_sections, but we must add
15745            the entries now so that we get the correct size for the
15746            .dynamic section.  The DT_DEBUG entry is filled in by the
15747            dynamic linker and used by the debugger.  */
15748 #define add_dynamic_entry(TAG, VAL) \
15749   _bfd_elf_add_dynamic_entry (info, TAG, VAL)
15750 
15751       const struct elf_backend_data *bed
15752           = get_elf_backend_data (output_bfd);
15753 
15754       if (bfd_link_executable (info))
15755           {
15756             if (!add_dynamic_entry (DT_DEBUG, 0))
15757               return false;
15758           }
15759 
15760       if (htab->dt_pltgot_required || htab->splt->size != 0)
15761           {
15762             /* DT_PLTGOT is used by prelink even if there is no PLT
15763                relocation.  */
15764             if (!add_dynamic_entry (DT_PLTGOT, 0))
15765               return false;
15766           }
15767 
15768       if (htab->dt_jmprel_required || htab->srelplt->size != 0)
15769           {
15770             if (!add_dynamic_entry (DT_PLTRELSZ, 0)
15771                 || !add_dynamic_entry (DT_PLTREL,
15772                                              (bed->rela_plts_and_copies_p
15773                                               ? DT_RELA : DT_REL))
15774                 || !add_dynamic_entry (DT_JMPREL, 0))
15775               return false;
15776           }
15777 
15778       if (htab->tlsdesc_plt
15779             && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
15780                 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
15781           return false;
15782 
15783       if (need_dynamic_reloc)
15784           {
15785             if (bed->rela_plts_and_copies_p)
15786               {
15787                 if (!add_dynamic_entry (DT_RELA, 0)
15788                       || !add_dynamic_entry (DT_RELASZ, 0)
15789                       || !add_dynamic_entry (DT_RELAENT,
15790                                                    bed->s->sizeof_rela))
15791                     return false;
15792               }
15793             else
15794               {
15795                 if (!add_dynamic_entry (DT_REL, 0)
15796                       || !add_dynamic_entry (DT_RELSZ, 0)
15797                       || !add_dynamic_entry (DT_RELENT,
15798                                                    bed->s->sizeof_rel))
15799                     return false;
15800               }
15801 
15802             /* If any dynamic relocs apply to a read-only section,
15803                then we need a DT_TEXTREL entry.  */
15804             if ((info->flags & DF_TEXTREL) == 0)
15805               elf_link_hash_traverse (htab, _bfd_elf_maybe_set_textrel,
15806                                             info);
15807 
15808             if ((info->flags & DF_TEXTREL) != 0)
15809               {
15810                 if (htab->ifunc_resolvers)
15811                     info->callbacks->einfo
15812                       (_("%P: warning: GNU indirect functions with DT_TEXTREL "
15813                          "may result in a segfault at runtime; recompile with %s\n"),
15814                        bfd_link_dll (info) ? "-fPIC" : "-fPIE");
15815 
15816                 if (!add_dynamic_entry (DT_TEXTREL, 0))
15817                     return false;
15818               }
15819           }
15820     }
15821 #undef add_dynamic_entry
15822 
15823   return true;
15824 }
15825